I have a 1988 Corvette with a 4+3 Doug Nash transmission in it. I recently bought this car as a project car, the transmission needs a rebuild or a replacement. I have a couple options to choose from.

The TKO 500 would be perfect for me but it is out of my budget and cant do that.

so here are my option.

I could do a rebuild on the 4 speed transmission or I could get a new 4 speed for it, but someone told me that once over 300 HP it's not reliable. Im aiming for around 350-375 HP. Has anyone else heard about the 300HP and not reliable, also if i did do the rebuild how much would the rebuild run me? The overdrive unit is in good condition it goes on and off with ease.

Another option is going ZF6, I have found someone with a used ZF6 that wants to get rid of it for $600, but since i drive a 1988 i will have to do everything to match it up, and that will get expensive.

Another option is a Richmond 6 speed with around 30k miles on it. He wants 1400 for it, but i got a couple questions about the Richmond swap. Someone said that Richmond has a lot of problems. Also is the Richmond a direct fit? The guy with the Richmond said i can use my current bellhousing and everything else for the swap. Does anyone no anything about the Richmond swap that can give me some information on it.

 

bump

 

You're new here but you are asking old questions. Spend some time with the search function and the archives. If after reading what is available you have additional questions, then I'm sure that you will find help here. Good luck.

 

or how about you just answer my question posted there? no one has asked the SAME exact questions i just asked. if they have give me the link but i looked and couldnt find 1

 

The 4+3 was strong enough for the 87/88 Callaway TT so it should handle the higher hp. I know a lot of people hate the 4+3 but I kinda like it because it's a very unusual tranny. Plus I don't have the time or patience to throw in a 6 speed so I had mine rebuilt some time ago. My rebuild cost a little over 1k for both sides, if your OD is good it might be a little cheaper...couldn't say. Also if you do decide to rebuild good luck finding a xmission shop that works on 4+3.

 

ok now thats a real answer thanks 87beast. um 1 more question for you. i should be pulling the 4+3 in about 4-5 days. is it two separate units. what i think i am going to do is get the richmond 6 speed put that in there and be done with my transmission problems(i hope). i have heard ALOT of people say 4+3 garbage with 300+ hp so im not even going to risk it. ill just spend the 1400 on the richmond and then put it in there and sell the overdrive unit in my corvette already.(someone said it is worth a good amount of money because there so rare)

 

Comes out as 1 unit. Backbone is a PIA to take off on the diff. side. I recommend renting a tranny cradle jack....made it really easy for me - took under 2 hrs for me.