[Keithc8]

We can get [istons made for any application we need them made for. We have done some of the 390 blocks with .030 and .060 bore with the Scat 4.125 and Scat 4.250 stroke cranks. The cranks are only available with the 2.200 BBC rod journals which is the best way to go. You get a better bearing design and can use a longer rod.
The Edelbrock and Shelby heads are better than the stock type type heads such as the ones you listed. The stock 427MR heads can be made to work real well and are a little better than the Edelbrocks out of the box, this is why we port them. The High Riser head is a real good head and can be made a lot better with work like fillling the floor on the intake and porting. We have done some HR stock heads that we have ported and filled the exhaust and intake floors and got 380 intake and 260 exhaust. The problem is it cost a lot of money and people just go to the aftermarket heads unless the rules do not allow such as in NHRA Super Stock.
I feel in most cases to be on the save side I do not go over about 9.5 to 1 with cast iron heads and about 10.5 to 1 with aluminum heads. Hope this helps a little, Keith Craft