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Old 05-13-2015, 03:52 PM   #1
theuglyduckling
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th350 to t5 swap

Well through a previous discussion on whether to go with the 5.3 or the 6.0 for my swap, i have decided to go for the 6.0. The big challenge im seeing is going to be transmission. Has anyone done a swap from a 350 or 400 to a t5? sure there is performance in the automatic, but this is more of a fun daily driver(the t5 will maximize my fuel economy as well getting me around 20-25 on highway.) i've done my research so no need to argue about the fuel economy rating. I would like some input on doing this sway. i am really looking forward to having a 6 speed to back my LQ4 and the t5 seems like the perfect candidate.

Advice?
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Old 05-13-2015, 04:28 PM   #2
mongocanfly
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Re: th350 to t5 swap

To go from auto to manual may or may not be a big deal. You will need a ls flywheel (not cheap) clutch and pressure plate, clutch arm ,throwout bearing ,pilot bushing, and pilot bushing adapter,and a bell housing to go from ls engine to whatever trans you use. If your truck is auto then you will need all the clutch pedal assembly with bellcrank and all linkages from a donor truck.If you've never done a auto to manual conversion it can get overwhelming trying to make it all work right.I work with a guy trying to do a ls/manual swap into a mid 80s iroc and he is using a hydralic throwout bearing..they are having a fit trying to get it to work. T5 or did you mean T56?

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Old 05-13-2015, 04:44 PM   #3
kalbert
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Re: th350 to t5 swap

The T5 is a 5 speed and won't handle the 6.0, they really weren't able to handle the LB9 in the F bodies. I think you mean T56?
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Old 05-13-2015, 05:00 PM   #4
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Re: th350 to t5 swap

Your best bet may be try to find a whole T56 setup from late model camaro or gto....won't be cheap.
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Old 05-13-2015, 06:02 PM   #5
theuglyduckling
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Re: th350 to t5 swap

t56. i will probably use the kit as well as get the transmission from american powertrain. they will be able to have a full kit for my truck. The biggest challenge is going to be linkage and pedal system. i've already been told "go with a 4l80e cause its quicker!!'...... but i miss having a stick, and having 2 more gears will give me outstanding fuel economy for a 6.0 in a 76. I drive about 50 miles a day highway and have the stock 350 backed by the th350. not exactly fuel efficient, so this swap would pay for itself after about a year of daily driving.
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Old 05-13-2015, 06:13 PM   #6
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Re: th350 to t5 swap

Ha ha ..I wish I could classify my fuel mileage as outstanding...can't keep my foot out of it..by the way I put a nv4500 behind my 6.0 lq9
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Old 05-13-2015, 07:03 PM   #7
theuglyduckling
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Re: th350 to t5 swap

im either going to go lq4 or lq9. im not looking for crazy performance, but more so just a nice little mean street truck that makes a fun daily driver. but has a little to play with. so a lq4 with a cam would be perfect. the 6 speed is just cause i miss having that. i doubt i'll get great mileage half the time since i like to play, but for my to and from for work i should average low to mid 20's..... if i drive nice. do i need a whole new pedal assembly to include the brake and gas pedal? or is the full clutch assembly a stand alone assembly is one of the big questions.
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Old 05-13-2015, 08:43 PM   #8
MikeB
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Re: th350 to t5 swap

The clutch pedal arm should connect to the existing under-dash setup. There's a long 7/16" or 1/2" bolt on which the pedals pivot. Essentially, there are 3 vertical brackets -- right, center, and left. The brake pedal lives between right and center bracket; clutch pedal between left and center brackets. You can crawl under your dash and take a look to make sure it's setup to accept a clutch pedal.

Also, if your brake pedal is wide, you may need to reduce its size or buy one from a manual trans truck.

Auto trans brake pedal
http://www.brotherstrucks.com/prodin...number=BCP8700

Manual trans clutch and brake pedals
http://www.brotherstrucks.com/prodin...number=BCP8701
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1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes.
1982 C10 SWB -- sold
1981 C10 Silverado LWB -- sold, but wish I still had it!
1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming.
Retired as a factory automation products salesman.
Worked part-time over the years for an engine builder and a classic car repair shop.
Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

Last edited by MikeB; 05-13-2015 at 11:48 PM.
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Old 05-13-2015, 09:37 PM   #9
MikeB
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Re: th350 to t5 swap

Here's an under-dash picture I just shot with steering column removed. It shows the brake pedal attached in the middle, and you can see where I removed the clutch pedal on the left. The black shaft is simply a long bolt with a lock nut on one end. There is a plastic bushing on each side of the pedals.

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Mike
1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, AAW wiring harness, 5-lug conversion, 1985 spindles and brakes.
1982 C10 SWB -- sold
1981 C10 Silverado LWB -- sold, but wish I still had it!
1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming.
Retired as a factory automation products salesman.
Worked part-time over the years for an engine builder and a classic car repair shop.
Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!
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Old 05-16-2015, 10:18 AM   #10
theuglyduckling
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Re: th350 to t5 swap

much appreciated. it seems it will be a bit easier than expected. will i need to swap out floor sections for one with a hump though? or will just putting a hole in the floor for the shifter suffice? its my daily driver so this will have to be a weekend project or max a week in between work.
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Old 05-16-2015, 10:20 AM   #11
theuglyduckling
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Re: th350 to t5 swap

i was also wondering if it might be worth trying to fabricate and make a hydrolic clutch work. i want a good feel and great comfortable driveability with this set up so im going with a wide ratio t56 from american powertrain. it runs up to 3800 with the tranny and the kit. the 6.0 i'll rebuild from a junkyard with low miles on it. i found one for 400 with only 1200 miles.
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Old 08-28-2015, 01:53 PM   #12
thewr3tched
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Re: th350 to t5 swap

Bumping this thread to see if there are any updates. I plan on doing the same thing to my 86. I'm getting my 6.0 swap ready and plan on going the T56 route.

I've heard the hump does not need modification, but haven't seen many pictures of people doing this.
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Old 08-28-2015, 05:13 PM   #13
Krausmotorsports
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Re: th350 to t5 swap

Some may shun me but the last few years I've been messing with my 04 cobra while my squares sat outside. BUT!!!! Cobra is on the market so I can fully restore both trucks! Whoop whoop! Any how I learned a lot and I installed the Magnum T-56 in the car. I'm sure magnum makes some thing for the LS as well as far as bell housing. I have a extra 6.0 I was going to build a 408 then buy a Magnum trans with a well designed gear rations for my 86 but now i'm thinking of just putting in my Big Block 600hp N/a and still put in the Magnum! Considering the Magnum will hold and is rated for 1200hp. But it wasn't too bad at a cost of $2800 Shipped. The clutch was a twin disc rated for 1200 but also cost $1200
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