Bench racing with a friend of mine here suggested sticking around 9:1 with high boost numbers and the aluminum heads. He made over 700 with his 496 using pretty much the same setup. I guess I'm being too conservative?

Any particular reason to go with a Speed-Pro over a JE?

I'm on the hunt for probably closer to 650 to do what I want to do. I've collected a lot of parts... complete roller setup , heads. The rub was that I ran into unexpected issues with the short block hence having to redo it all. Bob Madura had pretty much told me that with a roller upgrade and 6-7 lbs with my iron RHS heads that we would be close to my goal if not beyond it with the 250. Needless to say, this has grown into quite the project.

I'll send you a PM. Thanks!

In this application I would really prefer the je pistons and tighten the clearance a little. But budget wise speed pro's are a dime a dozen and can work if everything is prepped, measured and assembled properly. If the budget fits go with srp or je pistons. There are better options than those but unnecessary for what you're doing.

Hey Tom. I wouldnt try 9-10lbs with a 250 blower.

Keep the bore size as close to standard as possible as to keep the walls thicker. The gains really arent worth it to go from a 454 to a 468 unless you absolutley need to.

I'd shoot for around 8.5:1 to 8.75:1 static, the right cam, 5-6lbs of boost, and go have fun with it. Low compression and big boost only works when you have enough blower to do so. Like lets say you did 8:1 with an 8-71, 420, then you can put some boost to it. A 250 trying to make 10lbs on a hot 454, is just gonna superheat the air and promote detonation. 6lbs of boost from an 8-71 will make more power than 6lbs of boost from a 250.

So go for a hone and truing of surfaces then? The bores look good (some scuffing in the cylinders that had issues... looks like it overheated if I had to guess) and still show a good crosshatch pattern. I really wish I didn't have to take this baby apart. The rod earing were great, and I don't recall having a crank installed in a block that felt so easy and smooth to turn. Make some wonder if the engine was gone through previously. Or if it's even the original short block.

I know this probably comes off as me being all over the place... the short block being an issue really screwed things up plan-wise.

Boost-wise, what's the most I should be on the hunt for with 93 and aluminum heads? It will be run on my friend's dyno so we'll be making sure she's tuned properly. Not going to leave anything to chance there.

My old combo which ran GREAT!!!!! For 3 years before I sold it:
Gen. 6 454 .030 trw 2399 Pistons 8.8 compression
Bullet hyd roller .640 lift
Merlin iron heads 120 cc chamber 345 intake runner, 2.30 intake valve
Blower shop 250 No intercooler
Single dominator 1050
Thunder bolt 4 with V6 box
700 hp , 5800 rpm 5 lbs boost

7.5-8 compression with small blower will be a waste of time. Think of what that engine would make for HP if you remove the blower , 400 tops
In theory if you add 14.7 lbs of boost you double the HP, so at 7lbs you add 50% more. That makes the engine 600 HP , now take the parisitic drag of blower and heat caused by spinning that little blower SO fast to try and make 7 lbs. that's another 50-75 HP loss. So you left with 525-550 hp. Besides the HP numbers the engine will not be efficient at all.
The engine your looking for has been built for the last 25 years by every engine builder there is. Learn from other people's mistakes and successes.

If they can just be honed, nothing wrong with that.

The 250 blower I wouldn't take past 6-7psi . I think you'll hit 650-700hp with those RHS heads, right cam, 6-7psi.

As for the 525sc being a turd, or not a turd, I guess that's opinion. But 525hp from a supercharged 454 isn't exactly killing it in the power department. While a very reliable piece , it wasnt a powerhouse by any means. But look at what was there. No compression, mild flat tappet, gm iron heads, tiny blower. Now take that engine, give it some compression, cam, better heads, better blower, and now youre making some horsepower.

:readinghelp:Great thread I'm thinking of doing the same next winter. Keep the advise coming please, especially from the ones that have been there done that.

Very much looking forward to getting this thing built and run on the dyno then finally in the boat enjoying the end product.

I'll say though that I'm probably overthinking a lot of this.

Lots of good points so far , prob should settle on your pistons and rings before you sweat the cylinder finish any more .prob wouldnt wouldnt theorize psi numbers too too much either .
a clean easy 5 psi through a efficient combo is as good as or better than 8 psi through a smog motor with a cam where the 3 psi extra is just bottlenecked boost and extra inlet temps really .
start looking for some extra pulleys now if you have the splined blower snout