Automatic transmission choices? (Page 1/1) TortillaTheHun FEB 17, 09:51 AM I recently picked up an 88 fiero and planned for a turbo 3800 swap, I'm shooting for 700 hp crank and ballpark 600 tq crank. The only two automatics that seem plausible are the 4t65 or the 4t80. I just wanted to know which one would be able to hold up to street/strip use the best. 82-T/A [At Work] FEB 17, 06:05 PM quote Originally posted by TortillaTheHun: I recently picked up an 88 fiero and planned for a turbo 3800 swap, I'm shooting for 700 hp crank and ballpark 600 tq crank. The only two automatics that seem plausible are the 4t65 or the 4t80. I just wanted to know which one would be able to hold up to street/strip use the best. That is a lot of horsepower. Is it normal to get 700hp from a 3800 SuperCharged? I've not typically seen numbers that high. If you're looking to go that high, you'll definitely want the 4T80. The 4T65-E HD is the one that everyone uses for high horsepower swaps... but the 4T80 was used behind the Northstar V8 and the Aurora... so that might be more likely the kind of horsepower you're putting out. Any more than that, and you're going to have to go to the Th-425 and longitudinally mount it back there. 1985 Fiero GT FEB 17, 10:01 PM quote Originally posted by 82-T/A [At Work]: That is a lot of horsepower. Is it normal to get 700hp from a 3800 SuperCharged? I've not typically seen numbers that high. If you're looking to go that high, you'll definitely want the 4T80. The 4T65-E HD is the one that everyone uses for high horsepower swaps... but the 4T80 was used behind the Northstar V8 and the Aurora... so that might be more likely the kind of horsepower you're putting out. Any more than that, and you're going to have to go to the Th-425 and longitudinally mount it back there. I think he said 3800 turbo, not sure how well they work with hp, but a turbo engine will be able to output more hp then a supercharger, as a supercharger is using power to make boost, with a few pros and cons. olejoedad FEB 18, 08:28 AM The 4T80 is the way to go at that torque level. The 4T65 case will crack out around the pump shaft. The 4T60E is actually beefier in the pump shaft area, and will handle more torque than the 65, but they are harder to come by now.