not all the castings are the same. i have found that the import metal is better than the gm casting.

the pits are out gassing little pores that are in the metal while it is casted 50% of all casting is done with a sand and the rest is in a mold .

but out of all the part's i did the supra turbo valve covers come out perfect . i did a set for a guy and his car was in one of them sport concept mag's. that made my day..

turbo:


non turbo:

(hint a 10 year old helped on these)

here are a few more



before and after :