Author Topic: 1985 Chev 383 Manual transmission conversion?  (Read 10431 times)

Offline Pwonu2

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1985 Chev 383 Manual transmission conversion?
« on: January 26, 2012, 06:04:56 pm »
I have a 1985 chevy swb 2wd truck with a 450+hp 500+tq 383, it currently has a th350 with a stage 3 shift kit and a 3000 stall converter, I'd really like to throw a 5 speed manual trans from a 90's or newer chevy truck in it, anyone got any info on a pedal kit and if there is a trans that can hold up to my power output?

Offline Jason S

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Re: 1985 Chev 383 Manual transmission conversion?
« Reply #1 on: January 26, 2012, 08:11:54 pm »
The clutch & brake pedal setup from an 80's - 91 C/K or R/V Chevrolet or GMC with a manual transmission would be hydraulic and basically a bolt in for your truck.

In the 90's, the GM pickups could be had with one of two different 5 speeds.  The NV3500 and the NV4500.  The NV3500 was, the best of my knowledge, found in 1/2 ton pickups with a 4.3 V6 or 5.0 V8.  The NV4500 was offered for 3/4 and 1 ton trucks with the 350 and 454 gas engines.  Both setups used hydraulic slave cylinders, so you can adapt the 90's clutch slave cylinder setup to work off the 80's clutch master cylinder.

Unless you were gentle with the throttle, the NV3500 likely wouldn't hold up too well behind your engine.  The NV4500 would hold up, but 1st is almost a granny gear.  Additionally, both transmissions have a rather long throw.

My $0.02:  If you're looking for a racing type transmission, you'd probably be happier with a T-5 or similar style transmission.
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Offline Engineer

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Re: 1985 Chev 383 Manual transmission conversion?
« Reply #2 on: January 26, 2012, 10:29:40 pm »
If your 383 is built using a reground 400SB crank then you will need a specially balanced flywheel for a 400SB. Don't try looking for an OE either. Chevy only built the 400SB with automatic transmissions.

I do believe that one is available from GM Performance Parts.
2002 Chevy 2500HD 4x4 8.1/ZF6sp RC/LB
2001 Chevy 2500HD 4x4 6.0/4L85E EC/SB
1997 Chevy Blazer 4x4
1994 Chevy K-2500 4x4 C6P 5.7/4L80E
1979 Chevy K-30 4x4 4sp 4.10
1977 Chevy K-30 4x4 4sp 4.10 454

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Offline Captkaos

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Re: 1985 Chev 383 Manual transmission conversion?
« Reply #3 on: January 30, 2012, 11:34:38 pm »
The NV3500 in the 1/2T trucks won't stand up behind a engine with that much power for long.  You need a passenger car trans like the WC T5, or the new Tremec.