Felx plate ????

[Blazin]

Are all one piece rear main seal flexplates the same? 87 one piece rear main seal flex plate on a 90ish one piece rear main seal motor?
Second a 700R4 flex plate in front of a TH350, will the TH 350 torque converter match the bolt pattern from the 700R4?

I am dropping a 90ish motor that had a 5 speed behind it into my 81 Blazer that has a TH 350. I have an 87 motor out that had a 700R4 behind it, it has a flex plate on it.
 
Just wanted a second opinion before I get ready to drop the motor all in and things don't match. I am confident based on my knowledge they will all work with each other.

[Captkaos]

I put a 700R4 behind a pre 87 with a TH350 flexplate and the converter bolted up fine.

[1976Scottsdale]

Same here.  Only thing I ever ran into was using a flexplat from a firechicken.  Just had to go get a 153 tooth starter.  I think the trucks were always the 168's when I used them.

[VileZambonie]

The major difference is between the big blocks with the 700R4. You can get a dual bolt pattern flexplate but make sure if you do have the one piece rear main you use the externally balanced plate.

[Blazin]

I bought a 168 tooth flywheel for a one piece rear main, it worked fine. Took some doing though because the first two idiots I talked to at Auto Zone couldn't handle finding what i asked for unless they knew how many bolts the trans pan had. Even after I explained to them it didn't have a trans pan as the truck the motor came from was a stick. They still couldn't get that through there skulls.