Is there a factory application for a 454 with a 700R4? I checked on Rock Auto for a few years and the ones I looked at were all TH400 or 4L80s. My friend said my TH400 flexplate would work, but once I got it bolted up, should have checked first, the torque converter wouldn't line up with either set of holes. I know I can get a flexplate from Summit or something, but I was hoping to get one really cheap from a factory application. This whole deal was supposed to get me OD cheap since I only paid $50 for the trans, I know it's good and I didn't want to spend much more money on this project. I am already bleeding money for other crap I thought was going to work. Sometimes parts you have lying around aren't the best way to go, lol

 

Apparently some 80's c20 trucks supposed to have had an option for a 700r4, but with 350. Does the 400 use the 168 tooth felx plate?

 

OK, I'll go back on Rock and check again. I have been looking at the C30s

 

I guess I could also ask, what is the bolt diameter for the 700R4 torque converter? It's a stock TC from an 84 Trans Am

 

IIRC the 1987 V20 Suburban came with a 700R4 and 454

 

Thanks for the reply. Rock shows the same two flexplates for basically ALL the 454's from the 70s to the end of the 80s regardless of the model.

It looks like Summit has a brand one for $30 and an SFI for $55, both with the dual converter bolt pattern. I think I'll just grab one of those.

 

Easy fix, drill new holes, or slot the existing ones. Did this many a time in the past. Remember the torque converter stays in alignment with the transmission from the torque converter snout going in the back of the crankshaft, not the bolt holes.

 

Eventually I will need two flexplates anyway, so I am just going to buy one. I don't like opening up holes, regardless if the snout is doing the work.

 

If you want it to look like the factory did the holes, use an end mill.

 

It's never straight when I try to make holes like that, hence the "I don't like opening up holes" lol