well the final steps to putting this monster back together have finally arrived. My question is, what torque converter do i use? The one from the transmission? I already have the 4cyl flexplate from a fiero.

Would be nice to know some of the specs of the motor.. Dyno graph, etc?

If it is just a typical SBC, with a mid 6000RPM peak power, a 2500-2750 converter would work fine.

Yes, you should use the torque converter from the tranny, the 4T65E-HD one. Of course you will find that it doesn't fit with the Fiero flexplate. It seems that so few people have done this swap that this doesn't get mentioned. You have to machine the flexplate for TC clearance.

Rick

[This message has been edited by couldahadaV8 (edited 12-21-2009).]

Its a 383 (360) with vortec heads, block hugger headers. Nothing to fancy. I want it to drive first before i try to crank out big numbers.

Have you made your exhaust yet? I'm curious how you cleared the tranny (on the rear side of the engine) where the headers exit.

I'm dealing with the one side still, where the transmission wraps around the motor. I'm thinking 2 flanges and some pipe should do the trick. Once i get around to it, I'll take some pics of the install and what not.

On a side note, if my goal was 400 crank hp, where could i get a tq converter?

Remember Torque converters are not ratted in HP, What parts are you putting on to get 400 hp out of a sbc? what heads, what compression ratio, what header size tubing, everything in this calibur will relate in what kind of torque converter you should get. Everything is based on your setup there is no really the best "torque" converter.
Prox

You will need to use a converter that fits the transaxle. If I recall the flex-plate needs to be modified but I don't know exactly what needs to be done. Your stall speed with the V-8 should be in the 2400-3000 rpm range depending on useage. The closer the stall speed (higher) is to the peak torque of the engine, The better your launch off the line will be if you plan on drag racing the car. The lower the stall speed it the more streetable the car will be or if you plan on autoXing the car.

When I built my 3.4L I had a custom torque converter made at Pro-Torque
http://www.protorque.com/


You may want to call them. Since they build the converter you may even be able to get one assembled that fits the 4T65 on one side and the Fiero flex plate on the other. The outside diameter of the converter is the same it's just the mounting that changes. They can also assist you with getting the correct stall speed.

Just a note that using the stock converter may change your stall speed when going to a V-8. The torque converter stall speed is based on the torque curve of the engine. So a V-8 with a lot of low end torque will work/act differently that a 3800SC that has a slightly higher rpm torque curve on the same converter. If the stall speed is way off it could make the car drive like crap.

This shows the 3 areas of the flexplate that need to be machined away to clear the TC; it shouldn't be a big deal since many stock flexplates have more than this machined away (after all, they are supposed to flex!). Sorry the pic is kind of big:



Oh, I did make my exhaust. Here is how the rear pipe clears the tranny:

Its a 383 (360) with vortec heads, edelbrock intake and carb, block hugger headers (2 1/2") mild cam.

Thanks for the picture. I was wanting to know if that header would fit. I can't power brake the car very high before it over powers the rear brakes. than it leaves with the fronts sliding! for my next engine I am going to build more top end power to kill some of the bottom end power ( and wheel spin ) My car weight is (with out driver) 2988 pounds,with all the street stuff, on 4 corner race scales. It has 58 % on the rear wheels at rest. And that is with the bat in the front. And no a/c compresser. When i had the 355/tpi engine in it it was a tire frying sumbitch. Next time I will run a roller cam and a victor-E intake to help kill the off idle TQ.

or get some sticky tires.