4+3 trans swap..
Thread Starter
Racer
Joined: Nov 2004
Posts: 445
Likes: 0
4+3 trans swap..
I did a search and couldn't find if anyone has done a 4+3 trans swap into their C3 successfully.
I have a built manual trans with all of the parts, except pedal, and am not enjoying the auto in my BB 73 convertible.
Anyone with experience in this swap...?
TIA
I have a built manual trans with all of the parts, except pedal, and am not enjoying the auto in my BB 73 convertible.
Anyone with experience in this swap...?
TIA
CF Community Team
Joined: Oct 2004
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From: Cape Cod, Mass.
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Probably not helpful to you but that 4 plus 3 tranny is a very problematic unit, especially the overdrive unit. The Borg Warner 4 speed is fine but the OD units were very troublesome and prone to failure. I have had a couple of them in C4's and they were a real headache. Most change them out for something more reliable.
Drifting
Joined: Mar 2011
Posts: 1,886
Likes: 9
Get an overdrive 5 speed. There are several vendors the sell entire conversion kits, complete with transmission, driveshaft, linkage, rear engine mount, etc. Kiesler Engineering is one place to start looking.
I'd love to install one of those myself, but I can't seem to find it in the budget. Yet.
I'd love to install one of those myself, but I can't seem to find it in the budget. Yet.
Race Director
Joined: Jul 2004
Posts: 12,679
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From: Scottsdale Arizona
IMHO, if you go through the effort of doing the conversion, get a good 5 or 6 speed transmission, especially behind a big block.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
I personally like the Doug Nash 4+3 transmission...My 84 was equipped with one. Many don't like 84`s ither....the only thing wrong with the Vette was the lack of horsepower....slowest Vette I ever had but that was fixed/helped with the addition of the GM-151 camshaft....When it shifted out there was an immediate substancial drop in RPM`s and the speed remained the same.....Actually it became my favorite Vette even with the Z-51 package that apparently I`m the only one that liked that feature in 84`s too. I would like to get my hands on the SOB that stole it from my daughter.....
CF Community Team
Joined: Oct 2004
Posts: 19,350
Likes: 5,240
From: Cape Cod, Mass.
2025 C6 of the Year Finalist - Unmodified
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2021 C8 of the Year Finalist Unmodified
2020 Corvette of the Year Finalist (performance mods)
2019 C1 of Year Winner (performance mods)
2017 Corvette of the Year Finalist
2016 C2 of Year
2015 C3 of Year Finalist
I personally like the Doug Nash 4+3 transmission...My 84 was equipped with one. Many don't like 84`s ither....the only thing wrong with the Vette was the lack of horsepower....slowest Vette I ever had but that was fixed/helped with the addition of the GM-151 camshaft....When it shifted out there was an immediate substancial drop in RPM`s and the speed remained the same.....Actually it became my favorite Vette even with the Z-51 package that apparently I`m the only one that liked that feature in 84`s too. I would like to get my hands on the SOB that stole it from my daughter.....
I definitely agree on the early Z51 cars (84/85). Great handling cars. The ride never bothered me. Like you, I'm used to all the old solid axle cars so these were fine.
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
I placed some 93 'Saw blades on it and was stolen a few days later before I even got a picture...shown here with 87 wheels......
.......16 year old Daughter #2 was the victum and in the car
CF Community Team
Joined: Oct 2004
Posts: 19,350
Likes: 5,240
From: Cape Cod, Mass.
2025 C6 of the Year Finalist - Unmodified
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2021 C8 of the Year Finalist Unmodified
2020 Corvette of the Year Finalist (performance mods)
2019 C1 of Year Winner (performance mods)
2017 Corvette of the Year Finalist
2016 C2 of Year
2015 C3 of Year Finalist
I trust you got your daughter back 
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