[Brutus_5150]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Badbird69:

Mondello says the solid main web 403's have casting #554990-4A or #557265-4A as opposed to the more common casting #557265-4B. I got to the point where I wouldn't bother even pulling the pan off a 4B block, but if it was a 4A block, I was all over it. But......well, you know......it's just another urban myth. <HR></BLOCKQUOTE>

When you say a 4B block, will it say 4B on the heads too, or 4A which I usually see?

BTW, I know Olds had some marine application 403's with a different cam but no clue if they were windowed or not, and I have no casting numbers.

I do know a buddy of mine a while back just threw a 268 Competiton cam, Performer intake, and Holley 650 into a 403 from a T/A, stuck into his 72 Cutlass and pulled consistant 8.5's in the eighth with a 3.42 posi. No bottom work, no head work, pretty cheap, too.

Holy ****. I just saw the date of the original post oh well. Good luck to ever reads this.