vogey

I have a 25' 78 carrera ss with 454 merc trans and trs outdrive, im not to sure on whats inside, it has a torker 2 intake Holley dp (750/850) stainless log manifolds. I havnt checked but was told it has rect port heads (could very well be ovals) it has rod knock and needs a rebuild, i bought a reground stock crank. And am lookin at hyper pistons 30 over, but for $10 more i can get the same pistons for 4.250 crank with stock rods. Seems all things being equal (gotta hot tank, bore, balance both set ups) $300 more for a stroker is a no brainer. Im just wondering if there will be a down side to goin bigger? Im lookin for 9.5-1 comp power under 6000rpm id like to hit 500hp also could use a cam recommendation?

Griff

The crank is what creates the stroke and you already bought a stock one???? Are you going to buy a 4.25 crank????

Go with a better forged piston like some SRP's. Log manifolds are junk.

Making 500hp from a 461ci is not very hard with the right parts.

dereknkathy

Pull your heads and see what you have for pistons, heads, and see what you have for bores.You might not need a rebore. And for all you know, you might have forged domed Pistons already. And you might have a forged steel crank already. It would probably take a little clearancing in the bottom of the block so that the connecting rods don't hit the block with the larger stroke crank.

vogey

Yes i would be buying the stroker crank if i decide to go with the stroker pistons, the 454 come out of a 76 monte Carlo in early 90s (according to p.o ) and since montes didnt come with 454s in 76 it really is a toss up. I suppose the smart thing to do, would be pull it apart figure out whats inside. I just figured on cast everything with original bores and 30 over being a safe bet of working out. You dont think speed pro hypers will hold up in a boat?

Trash

1) I've never heard anyone say "gosh this stroker motor is just too much power." Ever

2) Hyper pistons will work, but I'd recommend paying a little more for a forged unit.

vogey

I like were your going with that, ive read dozens of posts on this very question and it seems to be 1/3 sayin no brainer more cubes more power, 1/3 sayin stock stroke is more then enough to make so n so power, then the last 1/3 says everything being equal (comp, heads, intake ect) the stroker will make more torque but some how less hp unless u work the heads too

vogey

P.s im really tryin to get as much hp as can below 6000-5500rpm ive read lots on the trs out drive (basically bulletproof as long as u dont buzz it to death above 6000) the trs was actually main reason i bought the boat, it was between this and a 10yr newer boat that was same lenght and nicer but sbc (with rod knock) with alpha. It waa more of a cruiser then speed boat. But i didn't want to biuld a hot sbc then spit out alphas

airjunky

At least pull the valve covers and see what heads are on it . If they are rect ports , then start pricing gen 4 rotating assy with dome's to match a 489 with 120cc chambers possibly a matching flywheel and balancer . Make sure whatever cam is in the motor now is not a street cam .