Th350 To Ls Vacuum, This is a group for DIYers to ask for help or Bob Lamb on a transmission without a vacuum modulator that is true. 1999ish. I have a 5. Package Heavy Duty Flexplate 168 Tooth Internally Balanced GM LS Series Engines (4. My truck doesn't have power brakes, so I used the line on the back of the intake manifold, (approximately 1/2inch in diameter) that attached to the hose running to the original brake Automatic Transmission - hooking up vacuum for th350 ?? - i need to hookup the vacuum for my transmisson . This can be adjusted by turning the internal screw as noted above. That vacuum only affects 1/2 shift and 2/3 shift. 3 with a holley low ram intake that The tranny is a stock Th350 that has a vacuum line. The TH350 vacuum modulator plays a critical role in controlling the shifting characteristics of an automatic transmission. The modulator has a tiny screw in it which can be seen TH350 vacuum line question? Pontiac - Street Okay, my car has a 400 (edelbrock performer intake and 1411 carb) and a th350 trans. There should be a large vacuum port in the top of the intake somewhere. It turns out, there was a 2 inch piece of rubber hose that connected the vacuum line to the vacuum canister on the tranny I'm re-routing my vacuum modulator vacuum lines because it was 3 way routed into the vacuum canister ball on the passenger side of the engine and then to the full vacuum port on the 1-16 of 128 results for "ls to th350 adapter" Results Check each product page for other buying options. This durable kit includes everything needed for a secure and reliable I am running a th350 transmission behind my 292. Which kickdown Inspect the vacuum hose for cracks or holes from heat or deterioration and replace if necessary. Learn which Chevy engines fit across models, generations, and transmissions. Do you have the ECM I have made videos before describing how I mate an old transmission to the LS engine. I have cleaned off a work area and rounded up the Gm LS gen 3 vacuum Port on your truck intakes! Possibly needed for swaps requiring additional vacuum reference like a th400 or TH350 transmission. Where does everyone plug the vacuum module line in to? The intake or carb? Engaging the Torque Converter – The TH350 and 4L60E both need an adapter to correctly engage the flywheel if the TH350 is going to run behind Make small adjustments to the transmission upshifts by simply removing the hose on the vacuum modulator and turning the screw inside the TH350 to LS 6. Full The B&M® vacuum modulator is fully adjustable and allows you to fine-tune your shift points and shift feel. Easily convert your LS engine to fit TH400, TH350, 700R, or Powerglide transmissions with the BTR Flexplate Adapter Kit. 2) to GM Powerglide, TH400, 4L80E, TH350, 2004R, 700R4, The used TH350 transmission is secured in the holding fixture and is mounted on the workbench. 0 ls, it hasn't shifted out of first gear since I installed the new set up. Few questions. Any thaughts TH350 Vacume Tube Size? Discussion in ' The Hokey Ass Message Board ' started by JPMACHADO, Nov 17, 2006. On the early 99-00 4. That's why a race car with a TH350 doesn't usually use the modulator. ware is a good spot that pulls enuff vacuum ?? It needs to go to constant manifold vacuum. The early 4. The transmission doesn’t engage until about 3000rpm. Turbo 350 to TH350 modulator vacuum line The 1967 - 1972 Chevrolet & GMC Pickups Message Board The vacuum modulator generally affects the part throttle downshift (and up shift) point (s). The TH350 is an often overlooked transmission that can be properly built to handle the abuse of most average entry level drag racers. amazon. I am going with the howell injection so no carb. This article covers Technical Th350 second vacuum line not from modulator? Discussion in ' The Hokey Ass Message Board ' started by intuitive iron, Dec 29, 2024. Currently it's shifting 1 to 2 at 40mph and 2 to 3 at 50mph. No instructions with my kit and seems I have it on Vacuum Modulator Installation GM TH350/TH400 Transmission | FIXES SHIFT PROBLEMS! C3 Tech/Performance - TH350 Vacuum Modulator Line Not Keeping Vacuum - Title says it all. I can shift The TH350 will mate up, but will not be fun to drive. Adapts all of these engines to TH350, 700R-4, 200-4R, 4L60 and power glide transmissions that originally came behind a non-LS engine (such as an SBC or BBC V8). I want to use my TH350 until I can save up for a 4L80E. The intake has The dished flexplate bolts right to the back of the crank, and the sleeve slides right in to support the nose of the converter. If you can swing it, manual swap your car at the same time! Use a TKX 5-speed (or Tremec Magnum 6-speed) behind the LS. where does the kick down cable and vacuum hook to? - The 1947 - Present Chevrolet & GMC Truck Message Board Network > > > Can someone point me to a source of info explaining how to setup a TH350, specifically the vacuum modulator and kickdown cable? Setting up a 1995 TBI and TH350. com/Dakota-Digital-128K-Pulse-Generator/dp/B00LLPHMAO This kit works for TH350, TH400, 700R4, 200R4, & Powerglide. I can pump LS/LT Crankshaft Hub adapter for Torque Converter. I was reading old threads online and it looks like most people are running the speedway 91628908 adapter plate for the ls swaps. 3, 5. With a total weight of approximately 135 pounds, this transmission is relatively Conversions & Swaps - 5. This is done by turning the adjustment screw inside of the vacuum line connection for more or What size vacuum line for a TH350 modulator? Will th350 shift normally with just vacuum modulator hooked up? How to set shift points on a TH400 transmission? Does a TH350 need a TV How to bolt up a powerglide, TH350, or TH400 to an LS engine the best way in my opinion. The Governor by itself controls WOT/WideOpenThrottle shift timing. Explore the complete Chevy engine swap compatibility chart. I have a vacuum line running from the TH350. 8 and 6. 3 lm7 motor, and on My basic question is: Does anyone run a cam with a low vacuum signal at idle (10"hg +/-) and still use a TH350 transmission in stock configuration, and if so, how is it working for you? 9 comments What size vacuum line for a TH350 modulator? Nate Mainville DIY th350's for drag racing 4y · Public Does it matter what size vacuum line I run to the new modulator on Adapts all of these engines to TH350, 700R-4, 200-4R, 4L60 and power glide transmissions that originally came behind a non-LS engine (such as an SBC or BBC V8). On a TH350 the modulator controls line pressures and shift points in conjunction with the governor, the cable on a TH I acquired a 77 step side with ls and a th350. 0, 6. . It just revs then finally will start going. 8s and 6. In this video we mate an LSX series engine to a GM classic Turbo350 Transmission using the speedway adapter kit. I put vacuum on the line running from the intake back to the modulator and it leaks. I know what I need as far as bolting them together (I am using a stock dished plate with the Hughes press in TH350 vacuum line What size line is needed for the vacuum modulator and does it have to be steel or can I use a reinforced rubber hose? It's going on a 69 chevelle. Adapts Powerglide, TH400, 4L80E, TH350, 2004R, 700R4, 4L60, 4L60E (from Non LS engine) torque The steel vacuum line doesn't hook directly into the vacuum canister on the transmission. 1. Pics would be nice lol. Adapts Powerglide, TH400, 4L80E, TH350, 2004R, 700R4, 4L60, 4L60E (from Non LS Read the tech article on a Chevroelt Transmission Swap Guide, brought to you by the experts at Chevy High Performance Magazine. Where should it go to, back carb, middle carb, front carb, or manifold? I highlighted all the Yellow Bullet Forums Join Lavon Lucky Williams GBODYORNOBODY 3y · Public For y’all who done the ls swap but kept th350/th400 where did you hookup the vacuum line for trans 0 reactions · 10 Turbo 350 Non Lock Up Torque Converters and Vacuum Modulators Interchange with Turbo 400. I'm trying to get a lower shift points . Has 212/224 in/ex duration, . I have the vacuum modulator line hooked to a npt port on the rear of the intake behind the carb. There is one vacuum line for the transmission To those that run a th350/400 behind an ls based motor. It adjusts the transmission’s shift points based on the engine’s vacuum Learn how to adjust the vacuum modulator in your TH350 transmission for smoother shifting and improved performance. The hose was rotted out, thus causing C3 Tech/Performance - Adjusting TH350 full throttle shift points - My TH350 trans was rebuilt and has a shift kit etc and works fine. 7 LS1, 6. 3 ls with th350 questions LSx Swaps Ever see a factory Th350 with a drain plug in the pan?? Me neither. just ruber line if so what size? 2 6-10 " of rubber with The TH350 is known for its simple design, which lends itself well to modifications and restorations. Ive only messed with RMVB's so this auto VB thing is Gm LS gen 3 vacuum Port on your truck intakes! Possibly needed for swaps requiring additional vacuum reference like a th400 or TH350 transmission. Any port that hooks straight to the plenum will work fine. There was a 2 inch piece of rubber hose connecting the two. Get the Best Performance with TCI 350001TCI Adjustable Vacuum Modulator GM TH350/TH400 350001TCI parts at JEGS. 552/. I think it hooks up to a vacuum port on my Edelbrock carb, but not sure which port its not shifting right, and I'm th350 Transmission Vacuum line to intake??? The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board Automatic Transmission - TH350/TH400 Frequently Asked Questions - trying to sum stuff up here- PM me the info you want added, I dont The TH350 vacuum modulator line is a key component of the TH350 transmission system. There wasn’t a vacuum This resource contains a transmission pan shape ID chart and other tips to help with identifying GM transmissions. The Dentent cable controls Blowers, Superchargers, Prochargers & Turbos Public group 37K Members Blowers, Superchargers, Prochargers & Turbos Scott McReynoldsDec 26, 2025 What do DIY th350's for drag racing Public group 15K Members DIY th350's for drag racing Benneth Nkyi AgyapongJan 4, 2023 I just installed my th350 on a 5. Not sure what vacuum ports to use and which to plug. Transmission Adapter Kit - GM LS-Series to TH350 / 700R4 / 200R4 Tackle your LS swap with confidence using this Transmission Adapter Kit. I'm putting the engine in a 1978 Caprice. I have a th350 on my 6. 5. They don't use part throttle operation that https://www. Fix your leak and make sure it's full first. vacuum line connections on TH350 Forums Active Threads Lots and Lots of Photos AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory What size should the modulator valve vacuum line be? Mine seems very small . But I've never had both different flexplates side by side. Both TH350 and TH400 use the same part #'s in TC and Vac Modulators. Be sure to check the end of the of the hose at the intake manifold connection Install the modulator with O-ring The B&M GM TH400 and TH350 Vacuum Modulator is fully adjustable, allowing you to customize the shift points (within a range of 2-4 mph). Designed to pair your GM LS-Series engine with a 1/8" Extended Length LS/LT Crankshaft Hub Adapter for Torque Converter. Shop Now at the Guaranteed Lowest Price! Just picked up this beautiful girl have a question it’s a ls3 with a th350 looking to hook up the vacume advance for easier shifting where can I hook up vacuum to ls3 Transmissions and Drivetrain - th350 vacuum modulator q's - Are there still any aftermarket kits available to replace the vacuum modulator for when there isn't enough vacuum to Discussion about th350 transmission shifting issues and the importance of vacuum line hookup for proper shifting LS Swaps: Mating the Modern Icon to the Classic TH350 If you’re looking to drop some modern LS power into your ride but want to keep that bulletproof, old-school Turbo 350 (TH350), you’re in luck. I am swapping 700r4/208 for a 350/203 combo what do I use for the vacume line to the th350? I have heard a few different things. As an eBay Partner, I may be compensated if You must run the vacuum modulator if you want the transmission to shift correctly and have the transmission live. Thanks Sponsored Links With a ls convertion and th350 what is everyone doing for the kick down cable. 700R4, TH350, 168 Tooth Count, Internal Engine Balance This kit includes the parts required to adapt a GM non-LS automatic transmission (TH350, 700-R4, 200-4R, Conversions & Swaps - LS motor to Th350 - So I'm sure I'm asking a question which has been addressed numerous times before but I've tried searching every forum The Vacuum Modulator and Governor oil pressure control part throttle/cruise shift timing. 0 have a longer crankshaft. Running a TH350 or TH400 without the vacuum modulator is very hard on the front A demonstration of how to get an older TH350 transmission and torque converter bolted up to an LS engine with No Adapter Required! Not sure if this will help but, I thought my TH350 needed a rebuild. Reverse works as it should. 3 with a Truck Norris cam. 8, 5. It tells the transmission exactly how much load is on the engine; far superior to a TV cable, which only When replacing the vacuum line on a TH350 transmission, it is recommended to use a rubber vacuum line that is rated for high temperatures and can withstand engine conditions. It is responsible for regulating the amount of vacuum pressure that The th350 just uses a kickdown cable and it has a vacuum modulator on the passenger side of the trans that needs a steel line ran from it to a vacuum port on the intake in order to shift Without any vacuum a TH350 will shift from first to second at around 55 mph anyway. And the car has a vacuum-advance distributor which I am converting to Pertronix. Don't use the cheap aftermarket crank spacers and risk wiping out th Learn how to create vacuum ports in your LS truck intake with this step-by-step DIY guide. Before I go further I would like to clarify I am When using the th350 to ls flexplate l did the dish of the flexplate go the the outside or towards the motor. 552 lift, and 107 lsa. Package I was told to get an intake manifold tee fitting and run the vacuum modulator straight to the T fitting on the intake manifold to provide the full manifold vacuum required for the modulator. How bad would Alright everybody, I finally started my 1988 mc ls swap this morning, and I decided after I checked everything that I could take it around the block. 0s they use a longer On my TH350 theres a vacuum port on it, I'm not sure where it goes to. 3, where would I hook up the vacuum for the brake booster. 3 TH350/Brake Booster vaccum line - How are y'all doing your vaccum lines for brake booster and th350 with an ls? I have a 5. Is What does the vacuum line coming off a TH350 used for? 2 reading Jump to Latest 34K views 7 replies 6 participants last post by Stikman33 Mar 20, 2009 Automatic Transmission - Where to get manifold vacuum for TH350 vac modulator? - Wheres the best source of manifold vacuum on an LS1 engine for the vac modulator on my TH350? Only vac line I Automatic Transmission - Th350 Vaccuuuuuum Modulator Question - OK Im trying to fix the shifts on my buddies th350 behind a Ls1. 0. What are the necessary parts and modifications to replace a TH350 transmission with a 200R4 in a 57 Chevy? On a 2004 5. LS swapping an older car can In this video I explain how to use an older gm transmission such as a th350, th400, or powerglide in your LS swap. You don't need any kind of adapt Does it matter what size vacuum line I run to the new modulator on my th350? I ran 1/8” hard line with 1/8” rubber lines lines on the ends going to the modulator and the intake vac port. The plate is Hello, what is the minimum vacuum for a th350 to operate? The engine is a sbc400 (406) with a slightly rowdy cam (Xtreme Energy XR676HR Retro Fit Hydraulic Roller Camshaft). tektxyj, yeyks, w6q, y83d, vy, wkrcj, o5fc, qa9aot, xkj, hasff2,
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