67dnixcoupe

I want to do a 302/ 351 heads set up is a 68 block ok to go with or get a 302/306 engine block?

2+2GT

Allegedly, they had higher nodularity, and they did have the thick 289HP main caps, but of course you can get these new.

cprstreetmachines

Same block, same parts. Block is actually a good bit softer than a stock block. About 20 points on a Rockwell test. It's flex is how it avoids cracking. Who knew being cheap pays off lol

67mustang302

It's not cheap necessarily. The Mexican foundries used higher nickel content. Anyone who's worked in engineering understands why that's a big deal in the strength of those engine blocks. Nickel is the key component in the super alloy metals, it's VERY expensive and results(when properly alloyed) in remarkably stronger metals. Inconel, 625+ etc are high nickel content....retarded expensive too, difficult to work with. If you look at the top level of motorsports(NASCAR, F1) high nickel alloys are common, and it's used a ton in the aerospace/aviation industry.

The mex blocks are a bit stronger mainly because of the extra nickel(probably unintentionally).

That said, it's marginally stronger, and given the age of most 302 blocks out there, just go buy a Boss block and have a MUCH stronger block.

andrewmp6

If i found one cheap i would use it but i rather spend the money for a aftermarket block.

OCHOHILL

I don't know from first hand experiance. I am not an engine builder. I have read that under a proper tune a mexican block will brake at a higher HP level than a non-mexican block. It doesn't really matter unless you are making more than 500 hp at the crank. That is the presumed HP level of a typical 302 block with a proper tune.

67mustang302

The way I see it, if you're pushing close enough to the limit that a mex block would make a reliability difference, you REALLY need to be building from an aftermarket block.