I helped oso member wayne272 on a build like that. Hotter crane flat tappet than you have, #134561 236/246 114LSA, same pistons , same heads. His heads i believe had the 2.19 mag valves, as his was a 454 mag originally, i believe the 420s had 2.25 intake valves. Anyhow, 177 blower of a 525sc, single 1050. Made 575hp at like 5400rpm, and 600ft lbs with 4lbs of boost. Ran good in his 31 Bullet. Nice little budget build.

I think I am gonna pull the trigger on that 525sc setup. I assume if I would have to swap valve springs, would that also be a good time to put inconel exhaust valves in?

yes and yes.

also upgrade to a bigger oil cooler.

I was thinking of a bigger oil cooler. I have the combo steering/oil cooler now. Can I just plumb in a second cooler? or would you just get a new larger cooler?

You need this. (B&M 250)
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[ATTACH=CONFIG]546548[/ATTACH]
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And 1 of these. http://www.mrcool.us/skin/frontend/d...ct-Listing.pdf
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[ATTACH=CONFIG]546549[/ATTACH]

Is it for sale?

what he said... a 250 would be a better route than a 177.

I would say, its winter time soon. Wait for a 250 to come up in the swap section. Get everything else ready for it and then put it on when it becomes available., much better then a 177. Or find a 671 blower shop setup. 177 end up being like little heat pumps, you start spinning them to make boost and they heat up and since you are staying with stock steel heads they turn out to be not that efficient.. The 250 would run much cooler and you wouldn't have to spin it as hard to make the same HP. And when you wanted to you could always swap the pulley and make a little more You are obviously ready for an upgrade, do it once and do it right so you can enjoy the new found HP. Afraid the 177 will leave you short. The 250 gets you where you want to be. Good luck with the project!

Imo, the 250 isnt a big enough upgrade from a 177, it is a better starting point however.

Even a 250 on a 454 making 5-6lbs of boost, will be 60+ percent overdriven, where a 177 will be 100+ percent. Imo, these small blowers work great on the street, where full throttle torque from idle to 5000 is the goal. Running 5000+ for extended periods in a boat, a larger blower like 671, 871, or 420 b&m is a better fit.