Hawkswings

I am doing a 2.8l to 4.8 Swap on an 87 firebird. My budget is shoestring but I am decent at making things work and or fabricatong what I need.

I have picked up a 700r4 k case from a 5.7l 88 blazer but it didnt come with a torque converter. Now I still have the 60 degree 700r4 from the 2.8l and was wondering if I could swap the input shaft on the k-case with the 60 degree or if it would burn up too quickly/ be too short?

The car has never seen winter (I live in the salt belt of ontario) so it wouldn't be more than a summer fun car for the time being. Eventually it will be upped to a real drag car with a proper built 4l80 or stick shift. But to get it back on the raod, this is what I have to work with. I have already called around and cant find a decent one to fit the budget atm. And I am not afraid to take the tranny apart and swap things over. Also the k-case was rebuilt recently.

five7kid

iTrader: (14)

By 4.8 I assume you mean LS-type engine. What did it come out of?

Was this a 2 wheel drive Blazer? I hope so. If not, sell/trade it for a 2wd TH700.

I'm not totally familiar with the V6 TH700, but the torque converter may fit your V8 transmission. But, if your engine really is a 4.8 LS, you'll need an adapter on the crankshaft, anyway.

Hawkswings

So I did do some swapping of parts between the 60 degree and 90 degree 700r4's. Aside from the metal thickness of the Sunshell (not much but 4x4 was thicker) and the length of the input shaft, most everything was identical, aside from the output length.

So I swapped out the output shaft from the 60 degree that was 2wd to the 90 which was 4x4. They are both 30 spline. I kept all the clutch plates and steels from the 4x4 as they were still new. I used the Sunshell from the 4x4 too as well as the rest of the internals. When I got to the input shaft and drum, I used the 60 degree just to test fit. I checked the converter to make sure it would slide on both pumps and it did.

So I buttoned it up and tested the length to the end of the housing for bolts and the center to see if it had the distance for the 4.8l (yes from a truck or conversion van. PO didnt remember was it was pulled from) The clearance for the bolts is dead on with only a 1/16 to 1/8 inch of play from the flex plate. I will have to make an adaptor for the center but it actually does slide into the center of the flex plate. So it's just to keep it aligned. I will need to drill some bolt holes.

I noticed that the shape of the flex plates for the 2.8l v6 and the 4.8l ls were both dished which is why I decided to try it. The 2.8l torque converter is also 10 inches across.

I did save the input from the 4x4. If/when I run into the issue of replacing the converter, I will have to take it apart to clean/replace parts anyway and can switch it back then. Will keep posted on how it works out.