Don't go down this path. You will be disappointed.
First, that "600hp" is NOT available from the 216-235 or 261 series of engines. That is only available from the LATER series that has WAY more crankshaft bearings and cana ctually spin some decent rpm without self-destructing.
Secondly, all the inline GM sixes we are discussing lack a fundamental requirement for decent power: a crossflow head (intake on one side, exhaust on the other). The 600 hp quoted was obtained on a lert series engine, with TWO small block V8 heads cuts, welded together, and remachined to make a crossflow head, needed a big supercharger, and had numerous expensive internal engine work including reshaped (not just ported) heads, etc.
The 172 hp predicted by the engine simultaotr program is incorrect because that program has no provisions for modeling a non-crossflow head. This introduces major error.
I went down this path a long way before realizing that it was doomed if you want REAL power. The best deal I could find in a month of looking very hard was a 261 (235 is too small) that could be worked to deliver perhaps as much as 250 crank hp MAXIMUM, and would cost $3500 to $4000 in work, plus shipping both ways, PLUS this assumes that the base engine you provcide is decent. So, really, this is about $5000 to $6500 to get maybe as much as 250 crank hp. There are better ways to spend money.
Note that back in the mid 50s, a famous engine builder puleld out all the stops on a 261 (not 235), that he bored to larger displacement, hand ported, raised compression, put in a cam wild enough that he admitted it was beyond what was streetable, etc, etc,. and got 190 crank hp out of it as his best outcome. So, with today's betetr techbniques and tools, I can beleive the 250 crank hp, but not anything more.
The Stovebolts are wonderful engines when used in reasonable line with their design objectives, but they will never be economically practical or reliable "powerhouses".
But hey, if you have tons of money to spend and don't mind a modest outcome, go for it!
I spent a lot less to get a 6.0 liter GM V8 with a dual carb Edelbrock intake that will deliver between 425 and 505 crank hp, depending on how much room we have for exhaust in my AD truck, and how well the dual carb RPM Air Gap intake performs relative to the proven Edelbrock single carb intake (which is breathtakingly good). And, I can get service and parts for it on a trip anywhere.
Jim G
