Well to start off here what pistons do you have. 2nd how do you know you will have to much compression? The engine that came stock with vortech heads on are not the aftermarket vortech heads that everyone is buying. If you give us more specs. on the engine we can cal. the compression and then everyone will give you a better idea of what do to.
I have not done this conversion. The question is: if you put GM Vortec heads on a stock mid 80's block will you be stuck with buying high octane gas? I'm talking stock flat top pistons here.
Vortec equipped late model trucks use 87 octane. I'm assuming that they must use dished pistons.
Bottom line: I have a stock mid 80's 350 in my Scout II. I'm about due for a rebuild. Should I spend $300 on rebuilding my heads or spend $500 on new GM Vortec heads? I want to continue useing cheap (ya right) 87 octane as this is my DD.