Originally Posted by waynger
Your right on the lack of weight change when turning the unit around, my engine was spaced 5" and yours isn't shows what I know.
I build a vega it was in hot rod also in the 70's it also had a th425 with the engine on the trans and it handled I thought fine. the fiesta had a 5" spacer to put the axle under the next main cap and it handled MAYBE better. I recently ran the numbers and moving a 450 lb engine 5" on a 90" wheelbase car only moves 25 lbs from the rear wheel to the front. Thats why I am moving the engine an additional 12"
One option rather than the long tubular spacer and drive coupling and such that you are going through would be to reverse the engine/trans, have the engine/trans/chaincase weight all forward of the rear axle and run a TM400 tailshaft housing with a short driveshaft to a differential (aluminum of your choice and flipped for rotation or don't know if a 4WD front differential has the correct rotation?) and your rear suspension. This moves the entire engine AND trans forward rather than just the tranny. Your limit to the forward setting is how much room you have and with the engine offset to the passenger side of the car you can basically center your tailshaft output and drive shaft. With your current 17" or maybe a little more you could possibly clear the front of the engine (now at the rear) with your independent drive shafts to the wheels?
Of course that means re-engineering all of the extension work that you have already done!! HA!HA!
It has been mentioned that there is a way to reverse the transmission output shaft rotation by swapping in some 400 series gears/parts into the THM425. But I haven't found anyone that has actually done it, just rumors so far.