Hi Guys, This is my first post, so please be kind. I know this isn't a VL or even a Holden question, but I thought you might be able to assist me. I have a 1969 350 Corvette. It presently has a Turbo 700 automatic transmission which fails to go into 4th. I should explain that I have had this car for a year and I was of the belief it was a Turbo 350 (as it only had 3 gears). Having now taken it to a new mechanic I have been told it is a T700 which fails to engage 4th. My mechanic has given me 3 recommendations: 1. Repair the T700 (I am not particularly interested in this option, as I have heard nothing good about the T700); 2. Install a rebuilt T350 ($2,500 plus installation); 3. Install a new T350 imported from the States ($3,500 plus installation). He is stating that the rebuilt T350 would be the best option as I wouldn�t get a warranty with the import. I should mention at this time that the Corvette is running the standard 300hp motor, with minor modifications (that I am aware of). Does anyone have thoughts on the best option to take up?

T400 is a much better gearbox

Quote: Originally Posted by aus880 [View Post] T400 is a much better gearbox Can I ask why you believe this is the case (just for future reference).

the turbo 400 is a great box that can take a heap of power ! but for something like what u have i would go the turbo 350 the turbo 400 will drain to much power

I'd go the turbo 350 in your case. Your car is already set up for it (cross member, tailshaft etc) They're cheaper and lighter than a 400 and you dont need to upgrade with the power you have. I'm pushing 500hp with a turbo 350. Turbo 400's are stronger however heavier and cost more plus youll need cross member and tail shaft modified to get it to fit. Toss the turbo 700 as they're pretty weak, even on a basic 300hp engine. Your trans builder is ripping you a new one with the prices he's quoted you. You could buy a working 350 from ebay, wreckers etc for under $400 and get a standard rebuild for under $1500 (quite easily). The only reason you'd be paying $2500 is if it were beefed up, full manualised and had higher quality parts in it to handle 500 or so horsepower. Hope that helps.

It sure does. Thank you. Given that I already have a T700 in her, wouldn't that mean I would already have a suitably lengthed tail shaft and the correct x member? I got a price to upgrade the T700 from Queensland Performance Automatics and they put it down as "T700R4 WITH A CONSTANT PRESSURE VALVE-BODY THAT CURES MOST OF THE FAILURES IN A 700R4 AND WITH ALLOT OF HIGH QUALITY COMPONENTS WOULD SET YOU BACK $3,800 INC GST". But this doesn't include R/R Labor, fluid etc. It seems a little extreme, however if I converted back to the 350 or the 400 I would have to get a new tailshaft, x member etc. Does this have any influence on your decisions posted above? Does anyone know of a good reliable trans shops in the southern or western suburbs of brisbane?

Really depends on what you use it for. City / country driving etc. Remember you'll get a overdrive gear with the turbo 700 which is nice. Better fuel economy etc. if you drive it a lot or country. A 'built' T700 will be tough also. Well capable of handling your 300 hp engine. However if your after something that will handle abuse i'd go the T350. T400 is a tough box but as said before unnecessary on a motor like yours.