GM Bowtie block "184" max bore?

[Abbottracingheads]

Call Marvin Shaw. The WOP shop can do it.

[Keith Morganstein]

We have no reasonable access to that test. I hope to hear from some builder who has experience with that specific block casting.

Buy your own ultrasonic tester. They are inexpensive these days and they work

https://www.ebay.com/p/Sseyl-Um6500-Han ... 3052318353

[Frankshaft]

PDQ67------ a 4.250" bore in a 4.400" bore center block would only leave .150" between the bores, are you not thinking of the fairly new 4.500" bore center block??? Dart machinery offers this block in iron (and) aluminum. The MAX. recommended bore diameter for this block is 4.250", and that would leave .250" between bores. A 4.400" bore center block (original S.B.C. design) at 4.185" leaves one with only .215" between bores. Mark H.

You are correct, but, it works. I had 1 Dart Iron Eagle block at 4.250 for years. It never lost a head gasket. And it wasn't a mild deal. Bill Mitchell did in fact sell a 454 that was 4 inch stroke. And 4.250 bore. Its kind of dumb to take a brand new block to the limit though.

[swampbuggy]

Thanks Frankshaft for your reply, it makes me feel better about going to 4.185" on my NEW block. It is shy 4.125" as received from Dart Machinery. There are small holes in the deck appx. .250", when you view down into certain ones which line up with the outside of the cylinder bore you can see that the cylinder walls are THICK, and even at 4.185" they are STILL gonna be THICK, i am happy to see (say). BTW what is the purpose of those holes, let air get out ? Mark H.