I bought a mark iv 454 from a speed shop that was rebuilt and when I bolt on the flex plate its closer to the block on the right side then it is on the left side. I found out the hard way when I tried to bolt up the trans and it wouldn't go graemlins/angry.gif . I assumed the flex plate was warped and they sent me a new one but even the new one is still crooked, on the right side I get 7/8" and 1" on the left. I realize the flex plate only goes on one way, the three holes that are close together on the flex plate line up with the the 3 holes on the crank (middle is not tapped, for a dowel i guess), and the raised sections face the torque converter. Both flex plates are brand new so I figure it has to be something that I'm doing wrong redface.gif . Any help would be greatly appreciated, I'll take any suggestions!

Are you sure that you are putting it on properly? It should have a slightly rolled inner lip and if put on backwards it could seem warped since it's not sitting flat on the crank. Also make sure
it's tightened in a star pattern and to torque.

I'm pretty sure its on the right way because the raised sections on the flex plate have to face the trans/torque converter and I did see the depression where the flex plate meets the crank. I also used a torque wrench in a star pattern, I even tried doing it in steps (30 lbs then 65 lbs). This thing is really kicking my @ss!

rn, (Name ???)
I have yet to see a new flex plate that is perfectly straight. Kind of sad, but the truth. Especially the ones with a weight welded to them, I think the welding warps them a bit.
I have never had a problem using them like that, once you bolt it to the converter, it will be straight. The only thing I am wondering about its the fact that you say you are having a problem installing the trans. A 1/8" warp should not cause any problem installing the trans. Actually the converter is usually about 1/4" away from the flexplate if it is all the way into the transmission front pump. I think you might have another issue with the trans not going on properly.
The only other possibility is the very rare probability that the crankshaft flange is bent. I seriously doubt it, but you could use a dial indicator to check.
ALSO..... you really should get a dowel pin for the crank to make sure that the flex plate is installed in the correct position. You might get it right, but someone else in the future might not. The dowel is only about $4 from GM. I am really surprised that the crankshaft does not have a dowel in it. Are you absolutely sure it is a 454 and not a 427 or 396 ??

Thanks for the info Bill, the first thing I checked was the casting number on the block before I started bolting on the other parts. The first flex plate was out alot more than 1/8 it was atleast a 1/4 and I didn't want to force things together. I too thought it was the converter not going all the way on, so I had a friend stop by and he put some black grease on the tip of the hub to see how far it went and it definitly went all the way on. When I measure from the trans case to theconverter its about 1" so its going to be very close on the left side because I get about the same measurement from the flex plate to block and I know most of you guys say the converter should spin without hitting the flex plate, I might try to hook it up tonight and see what happens. I don't know what else to do? Thanks!

Red,
Just so you know...454's and 427's use the same block, so the casting number does not mean much. And yes you should be able to spin the converter with the trans bolted to the engine. If you cannot...find out why.

I got the trans bolted to the engine and the converter does spin without hitting the flex plate graemlins/hurray.gif ! Its real close but I guess thats the way its gonna be since I'm way over budget on this project. I also talked to my mechanic and he also said the flex plate may flatten out when all the torque converter bolts are in. Thanks for your help!