The 4.25" stroke crank in a +.030 over 390 would net you an easy 445 cubic inches. To get around the camshaft to rod clearance issue, the SCAT cranks use the BBC rod journals which is really good 'cause the aftermarket rod situation is excellent in this respect. In my particular combination, I used the 6.700" BBC Eagle H-Beams just to keep the wrist pin out of the oil lands but I could have used the 6.800" rods just as easy.

The heads were ported C4AE-C with CJ sized valves, bore was 4.080, compression ratio was 11.1:1, Crower roller cam with .625 lift, PSE two piece single plane single four intake manifold, 1.76 roller rockers, and rotating assembly was internally balanced. The pistons were the TRW 2292's that I had cut ~.100" off the deck portion and retained the dome. This combination ran for three years in my altered roadster with 9.20's @ 143 mph being the norm. A broken spring (I was running triples) would slightly slow the car down to 9.30's but would kill the mph.

Valve spring breakage in the last year of running got bad enough that I eventually pulled the engine and replaced it with a 427 bored and stroked out to 458 CI. The one unique piece on that stroked 390 that I hadn't done before or repeated since was that I had the distributor running off the very front of the camshaft while I had a dummy distributor stub in the intake just to run the oil pump. The idea here was to isolate the distributor from the oil pump and stop any harmonics from the oil pump that could upset the ignition. Switching that back to a conventional ignition while the engine was on the dyno was something I wish I had done now to verify if my reasoning in this case was valid. It sounded good at the time and now that I think about it........ I believe I'll have to take another look at that again.