SB

iTrader: (1)

Car Biz just posted a good build up for your parts list.

As for cast iron intake, well, good luck performance wise. You could try to hunt down an older marine aluminum intake that has bronze liners or simply find someone to hard anodize an aluminum intake for you.

I can verify that it makes them 'electrically dead' as I've had to run a ground to the coolant temp sensor to make the sensor work. LOL.

Artate78

Wow I've never heard of that. What is all involved in that process?

gsxr1216

you dont need aftermarket heads or anywhere near that compression to make your goals.

my Gen IV 454 MAG stock bore, stock crank, stock pistons, stock heads (rect port OEM '90 454 MAG heads with no mods other than rebuilding them) with air gap intake an 850 carb and mild custom roller cam made 470+hp@5200rpm. cam wasnt anything crazy since i have silent choice with short risers so the cam specs had to be relatively tame to prevent reversion.

i also have my OEM 454 MAG aluminum highrise intake with the brass liner in it that i would sell if your interested for your build.

good luck!

Artate78

Is the intake dual plain? If so how much

MILD THUNDER

iTrader: (3)

I suggested the Dart 308IE heads, based off the assumption he didnt have any heads right now. Even if he had some stock gm rect port heads, sometimes by the time you rebuild them, its almost a wash to just buy a new set of heads. Especially if they seen salt.

For me, with Iron heads I'd keep it somewhere around 9:1. Aluminum heads, I'd go 9.5-10:1. If you think you'd put a blower on it down the road, aluminum heads and 9:1 max.

gsxr1216

Yes it is. $150 i guess??

pantera232

I am having problems getting my new build to spin high rpms, my cam guy is telling me to get rid of the 3/8 fuel supply and go bigger, the max rpm i got out of it was 5000, im running 781 heads but the smaller valves and a bob m cam with .6 lift, with air gap intake, 750 holly, small dome pistons. , 462 ci. Any ideas

Artate78

I bought the boat off the Internet only looking at pics. Freshly built 468 500hp 70 mph boat. Guy seamed honest we talked back forth for cupple weeks. So we made the deal big mistake. Got the boat straight to launch. fired it up Pulled off idled out. Went to give some gas no power. Back to launch pulled dip stick water in oil. Man I was sick. So go to fix head gaskets pull heads. Three shattered melted pistons. Then I was really sick. So here I am.

Block was no good so got new block
But every thing else is good
Gm big ovals 290 heads full roller rockers 219/188 valves
Comp cam .505/.515 .262/.268 112 lsa Part# 11-232-3
Gm oval port intake part#3854100
Holley 800 DP
Machine sHop said he could work the heads a little and get them to flow to 48 to 4900 rpms. Witch the cam stops at 5000
All this stuff is like new was a fresh build he just blew it up then passed it on to my dumd ass
So my question is how much hp would a .030 over 454 9 to 1 ish make with all the parts listed

pantera232

Man thats hard to say from what ive read 420 hp, mine should be a 450 hp motor but im chasing this fuel idea now to see if i can pull the 5300 rpm the cam is rated for.. sorry to hear, Ive heard good things about the 290 heads, maybe my 781 with smaller valves are my limiter in power. What cc are the 290 heads

SB

iTrader: (1)

Yup, heads are killing you.

Long time ago has a mild 9:1 454 small hyd cam street car than ran 12.80's with stock 781's. Put on Merlin Oval Ports (bigger valves 2.19/1.88) with nothing else and dropped to 12.20's and gained bunch of mph.

Anyhow, stock small valve oval ports don't do much in the power department. We run bigger valves in 'street' SBC's than you have in your heads.

Edit in: of course I can't answer on your tunin nor rigging (which kill many boats performance) without taking a 'look see' of what you have going on. Can tell you, as i did, those heads are killing airflow ie: power.