Dart SHP Pro block

[Dragsinger]

Question;

in ref to the SHP Pro block, are the 4.00 bore and the 4.125 bore the same casting? Can either block be bored to 4.155?

Thanks,

[Roundybout]

It's the same casting. Believe it can be bored 4.165 max. but I've seen some go a little more.

[1989TransAm]

Yes, at least they used to be. I assume that is still true.

[kimosabi]

Using two different casting molds just for that is not cost effective and makes no sense.

[fdicrasto]

Max bore on that block is 4.200" according to Dart

[redliner]

Max bore on that block is 4.200" according to Dart

WOW!

[pdq67]

What aftermarket SBC block is it that will bore to 4.25?

And I am pretty sure there is a matching head gasket for it at 4.25" bore.

pdq67

[Frankshaft]

What aftermarket SBC block is it that will bore to 4.25?

And I am pretty sure there is a matching head gasket for it at 4.25" bore.

pdq67

Technically, any Dart or world cast iron block will. Even a stock 400 block will. I have had 1 engine over the years at 4.250. It was a Dart 9.3 deck iron eagle. I wasn't the genius that originally took it that far, brand new nonetheless, but it ended up in my Care for years.

Fel pro makes a full round 4.250 bore head gasket that's .051 thick. The above engine NEVER had head gasket issues. It was fairly high compression.

I would NOT recommend going 4.250 on a stock block for obvious reasons, but, if you had a Dart block, got it cheap, and it was "used" up, why not. World Products actually had a limited edition 454 sbc, that was 4 inch stroke. It worked fine. It just isn't practical to use up a brand new block right from the get go unless your made of money and don't care