I currently have a 157 tooth flexplate with a "small" bellhousing C4 in my Mav. I have another C4 I want to swap in that has the big bellhousing. Assuming I use the torque converter from the small bellhousing trans, can I use the big bellhousing C4 with the 157 tooth flexplate? If not, I guess I have to decide whether I want to swap flexplates or bellhousings....
Can't use the big bellhousing with that TC and flexplate. The depth is different, and the starter won't mesh. I had this problem a while back too... Best thing to do would be to swap the smaller bellhousing onto your other C4 since you already have the parts for it. I don't think there is any advantage to using the bigger one, and at least you'll have more room for things like exhaust, linkages and cables later on.
You CAN bolt the small bell on the big bell case and use the small converter and 157 tooth flexplate. You will have this funny looking rib just behind the bellhousing but everything WILL work.
I had a feeling this would be an issue. You're right...I'd rather have the small bell. I just hope removing the bolts isn't too hard. I tried to do a swap like this earlier this year on a GM 4L60-E and the bolts had "grown" together with the transmission case and I broke one before it ever came out. Of course those are those stupid Torx head bolts...the ones in the C4 are good ol' hex heads, so I think they'll come out fine...
Yep, that's what I did! I think the cases on mine were identical though: ...That's before I swapped the bells.
