goin to freshen these up was wondering if adding super chillers to these would make that big of a difference.they are single carb type,with these blowers what horsepower could i expect? i spin them at 5000in the heat of summer to 5300rpm in spring. should i prop the boat to go 5500rpm.also these have around 90hrs should i freshen or add the coolers and wait one more year to freshen

Do a leak down test. If it shows OK, go another year. Put a chiller on, crank the boost back up to where it was without the chiller & take it easy on the drives.

t.t.t

Johnny,
I think I told you about an old set of motors I had but in case I did not here you go:
509ci
8:1 static
superchillers
dual holleys
brodix heads
They made 805 Hp at 6200 Rpm
I turned them 6400 in the boat

I pulled the boat yesterday so I will have those oil coolers etc in the next couple of weeks. Give me a call I still have my cam card from the 509's.