[HWYSTR455]

Technically, any 67-74 block would be fine, and even some of the 'select' blocks from 75-78. Those are supposed to have the higher nickle content, but that is splitting hairs.

I wouldn't worry about finding an engine with the heads you want, since that may push the budget higher (sellers of 'performance' engines may try to get more for people trying to restore). And since you have timing covers that aren't the oddball 69 ones, you don't have to worry about that either.

D-port/Round port is probably where you're finding the fit difference, as well as slightly due to the brackets. But, a 400 can breathe fairly well on nice manifolds, so you could always go that route with round heads. Ds you might as well use headers, since I believe you still have a set from the 421, correct?

I think you are dreaming if you are thinking cast pistons, especially OE ones. You're begging to blow it up that way, especially with a manual. Age/fatigue is your enemy. A bore isn't that expensive, and is good insurance for a number of reasons, bore clearances and ring seat/seal are some of the other biggies. It's not the fact that those parts would be a loss when they let go, it's the block. Those KB forged with a 14cc dish are only $350, not even sure you can get NOS cast for that. And it's what, maybe 20 bucks a hole to bore and hone? I think the last block I had tanked, bored, honed, and cam bearings/freeze plugs done for $280, just to give you an idea. (I have the reciepts, can verify). Oh, and oil gally plugs too. Think it was $350 to cut & polish a crank and balance the rotating assembly. $150 to square the decks, and $150 for align bore (mains). That's all from my head, but that's close I'm sure.

I'm tearing down that Olds this weekend and taking the parts up to the machine shop over the next week or so. When I go to assemble, maybe swing by, just to have some first hand knowledge maybe (and a few beers!). For the most part I can assemble the short block in a day, will have all the prep stuff taken care of beforehand.

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