Manual 5 speed conversion?

[jhiggy94]

I am thinking about putting a manual 5 speed tranny into my 72 k20. I like the idea of being able to bang through the gears and also be able to have overdrive in the truck. I was thinking about most likely picking up a 90's 5 speed from the junk yard or something and swapping them out. I have never done anything like this before and I would love some opinions from guys who have done this. Was it worth the hassle? Also what is the best way to go about doing it? The truck still has the original 351 and the TH350 in it right now. Thanks for the help!

[SS Tim]

There are countless threads on doing five speed swaps and most center around a NV4500. So I'd suggest running a search for that and digesting what you can. It is not a weekend bolt in project but rather something that is going to take some planning and modifications like driveshafts and moving the transfer case and or the engine. If I were to make a recommendation it would be to start with an overhauled trans and not a junkyard takeout as the transmission has durability issues and a few production fixes. The costs are high and too much work to gamble on an end result. Might also want to dig around Advance Adapters site for more info on NV4500 swaps and quad4x4.com as well. If you must have a gearbox a factory four speed would be a near bolt in for the TH350.

[jhiggy94]

Thanks for the info! That definitely gives me a good place to start!

[RManson]

I used a T5 in my '68. All the details here

[SS Tim]

A T5 nor a T56 are a good choices for a 4x4 much less a K20 intended for towing.

[RManson]

Well he never mentioned that did he? lol

[burnin oil]

Wouldn't want the T5 with 4.10-4.56 gears that came in a K20. I watched a buddy blow one up in a stock mustang with a 3.27 rear. He was barely rolling backwards and came of the clutch in 1st. Big bang! I looked at all the options for a healthy small block and the NV4500 is the olny choice. Bad thing is it is not a performance oriented transmission but it will take the abuse.

[67 chevelle]

one thing that changes between 67-72 trucks and the 90s is flywheels , the older are 2 piece rear main , the newer are one piece , other than that its pretty straight forward

[Don Quixote]

I have heard of this being done but when I think about doing it, I remain thankful for my 465. I like the granny gear and I would love to have an OD and a gear between 3rd and 4th. I switched to 3.73s in the rear which yielded better cruising speed but terrible downshift capability.

I still keep the old box because it is easy to maintain and no worries of mods, &c. It is also much smaller in size and you may already have the cutouts in the frame to make the TC and all work.
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[wraprail]

Originally Posted by RManson

I used a T5 in my '68. All the details here

Couple quick questions about your T5 install and that article you linked in CC trucks. They claim to use a factory truck iron bellhousing mated to a T5. Curious how you did yours and how long their input bearing lasted.

Sorry for the threadjack (again)
Thanks
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[LMREESE]

Check out Novak adapters. I put a Borg Warner T-18 in my truck and that site was a wealth of knowledge. The T-18 is just a four speed but I always said I had four on the floor and a fifth under the seat
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[RManson]

Originally Posted by wraprail

Couple quick questions about your T5 install and that article you linked in CC trucks. They claim to use a factory truck iron bellhousing mated to a T5. Curious how you did yours and how long their input bearing lasted.

Sorry for the threadjack (again)
Thanks
Posted via Mobile Device

That's correct, I retained the factory cast iron bellhousing as well as the stock flywheel, just had it resurfaced. The input bearing was fine when I pulled the motor out last month after 8,000 or so miles over the last year. PM me if you have any other questions.