...who couldn't get logged on here for some reason:

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the resurfacing looks like crapola. the weld up looks amateurish.

....I wouldn't install that head on a lawnmower.

the HGs control the size of the passages to direct coolant flow. The size of the passages....those holes....are the results of the casting process. bigger holes makes doing the molds for the casting easier. [and easier to get the residue of the casting mold media out of the finished casting.]

the BCP heads have bigger casting holes; thus, they have BIG Coolant Passages. as well as about 2 pounds less alloy in the casting. they were 'adequate' when sitting on 92mm bores, but not adequate on top of 96mm bores.

...also, the BCP heads do not handle high boost levels very well either.

people have welded up....NOT welded shut....some of the passages on BCP heads to increase the strength for boosted use. but that is a bandaid approach at best.

the guy needs another head. he got ripped off.

.....because IF that head was that badly corroded around those passages that were welded closed, or partly welded closed, then the corrosion further inside the head.....not visible to the eye.....is bad enough that that head should have gone onto the aluminum recycling pile.

like I said: I wouldn't use it on a lawnmower.

thickness of a new head: 146,1mm......5.7519in

max shaving of 20 thou off allowed....resulting in 145,6mm thickness...5.7322in

.....I do not like to use a head that has been shaved 20 thou. for boosted use, NO WAY. for NA use: only with great reluctance. I do not like to have to go more than ~10 thou. because then it becomes a matter of the cam bearings journals being out of alignment.


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Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.