700R4 vs TH400 TC length??

[SkysTheLimit]

OK, here's the deal. I FINALLY got my big block bolted in to the K5. Originally it was a 350TBI and 700R4. I want to keep the 700 (OD) and I bolted up the big block but seem to have 1 problem. The flexplate doesn't seem to touch the torque converter. It's about .5" off. The big block was originally mated to a TH400. Is there that much of a difference? I thought it would be a direct bolt up no problem. Is the TC pushed too far into the 700? can i just pull it out to meet the flexplate or do i need some spacers or a different flexplate? I'm hesitant to replace the flexplate because it was balanced along with the whole rotating assembly of the motor. Spacers seem like a bad idea. I'm laying down ALOT of power and I can imagine them shearing off. (then again i'm impressed all that holds it together is 3 bolts anyway). pulling the TC out seems like it wouldnt be fully engaged on the tranny at that point and asking for trouble?

Am I boned?

Thanks guys

 

[4X4HIGH]

When the TC is unbolted it will move rearward about 1/2". You have nothing to worry about, pull the TC forward and bolt it up. A SBC and a BBC are identical in distance from the motor mounts to the bellhousing. The overall length of a BBC is 1" longer than a SBC but that 1" extra length is forward of the motor mounts.

 

[SkysTheLimit]

Thanks Scott. That's what I thought but wanted to be sure.