I have the 350 out of my 87 GTA that I plan to put in my 71 GMC pickemup this weekend. Ol' Blue... I want to ask about bolting the truck tranny to the 87 block - will the 87 flexplate match the tranny? I'm assuming the truck has a TH400 as original equipment but if someone knows differently please let me know, I'm not familiar enough with trannys to know them by sight. I searched and found a post saying that a TH400 torque convertor has a larger bolt spacing than the 700R4 tq, but that a TH350 tq would fit both the TH400 and the late model flex plate. Can someone please confirm this? If the truck has a TH350 in it, will it match the 87 flexplate? I want to knock this out this weekend, so if I need to buy a tq I will. I could use the torque speq for aluminum intake manifold bolts too if someone has that info handy, Edelbrock RPM if that makes a diff. Thanks.

 

It will fit fine.

The only difference is in the two flexplates is the bolt pattern for the crank. The one piece has a smaller bolt pattern.

The bolt pattern for the torque converter did not change.