i am trying to rebuild a trans for a 3500# street/strip/track car with an as yet unbuilt, healthy big block. the car is more road course than drag, and is AWD, using an np242 tcase. i plan to use a th400 because they are far less $ than a manual with similar torque capacity, and there are lots of parts to mate to a variety of tcases. so, i went to the u pull it last fall, and got _most_ of a 1979 caddy th400 that had been rebuilt and put in a 76 grand prix (short shaft). the rest, i pulled from a 1967 caddy with switch pitch. u pull it has its advantages i kept the thing in pieces until now. my questions: 1. i have the forward and direct clutch drums/pistons from both transmissions. the older ones: stamped steel pistons, forward drum has two quarter-inch holes on one side, and the direct drum has a checkball in it? the newer ones: Al pistons, the forward drum has a single 3/16 hole in the side, the direct clutch checkball is in the piston? which of these should i use? how many springs? 2. intermediate sprag or roller? i have both. 3. previous builder put lots of holes in the forward and direct clutch hubs. i only have one set. should i look for replacements? Ron Sessions book thinks its ok... 4. 1 wavy steel in forward , no wavy in direct or intermediate, right? 5. it has teflon rings. should i look for iron? 6. is there any safe way to test the used SP converter? should i just swap it for a rebuilt? 7. brands/types of steels/frictions/bands? seems like most places just say OEM or HD, others say red or blue? 8. it has the plastic accumulator piston for the front band. is it really a good idea to turn this thing over and/or take out the spring? 9. what other mods to VB? 10. any opinions on manual VB? specifically interested in how they affect engine braking, and the ability to make one from a regular VB. not afraid to row my own, the th400 is thanks for any ideas- i want to get this thing buttoned up before the pile of parts spreads allan
hmm- this just got harder. the 79 model case has one less pump mounting hole. the entire boss where the SP orifice plug goes is missing. ok, so i get a new case. now i have another trans worth of parts to use allan
