o.k. guys. I bought a '91 toyota mini pickup with a 350 and a 700R4. I blew the rearend out after about 200 gnarly burnouts and decide to rebuild the motor along with the rearend and some suspension stuff. The thing is when we got the motor apart i found that it was already .080 over and my cylinders were egged a little, so i had to go .125 over. I've only ever heard of going .090 over. he said that he had faith in it, so we went for it. I had it hardblocked, 4.125 flat top Keith Black pistons, speed pro rings and bearings, crank was turned .010 under and polished. I have Comp Cams 280 magnum stick and springs and pushrods, Comp timing chain, Harland Sharpe 1.6 roller rockers. Victor jr intake, and a 750 holley(not a 4150), hedders. Now, my big question is, do you think its going to last?  

You'll find a 350 isn't happy beyond .030 over. The reason your .080 over cylinders are egged shaped is that they have no strength left because the metal is so thin. An eigth (.125) over just isn't doable, the block you have is scrap already.

Bogie

Sure its not a 400 block?

Not my engine I don't know, I trust the guy knows he has a 350 or a 400.

But given he said it was .080 over assuming that netted a bore of 4.080 which is not a 400 bore, then he went to .125 over which combined with 4 inches does make a 400 bore of 4.125. But it all sounds like an overbore on a 350 block. At .125 over, I'm surprised he didn't find the rusty side. Even if he didn't hit water, those walls are so thin that "Tuff Block" will be of little use.

Bogie

you should not of bought it with a .080 block, I'm suprised its lasted as long as it has, is it even a 4 bolt ? .030 is really as big as you want to go for a street car, come circle track guys will rebore to .060, but after that they go for a new motor, you're talking about boring double that, an .080 is like a transmission that leaks, in the long run it's better just to get a new one  

Won't last long.