Does the OP realize that a higher compression engine, well designed with a proper cam and quench will not detonate as much as a similar one with less Compression and less quench?

Further, does the OP realize it takes a considerably bigger camshaft (with quite a bit more duration than Hughes specified) to make a 500ci engine idle "super lopey"?

I am thinking that the op should just build what he has... I don't think Kevin is steering him in the wrong direction. He treated me well and I only bought some trinkets from them. I am gonna call him later today about some parts. Good luck with what you decide to do!

To many peas in the pot. We see it all the time on here. The OP needs to decide who is building the eng that he trust and go with that info. There are many ways to get what he wants and it seems he is getting about 20 different opinions here to confuse it even more. Decide on the one you will trust and go with that. That said I have bought some parts from Hughes for my 493 I built and they treated me great. Good service and fast delivery. Good luck to you. Ron

go with the 4.15 stroke i have done 3 of them now
and they are very reliable and rev all day long
one with 915 heads 2.14 8.18 valves comp hyd cam rpm 440 850 demon made 450hp @ 5000 and 550 tq @3000 small cam
one with rpm heads 6pk solid roller made 600 hp @6000 600tq @ 4000
one with victor heads solid roller indy dp 1000 cfm hp carb that i have not fired yet
the 4.15 is a true street strip combo that works good
if it aint broke don't fix it