Looking for 425-475RWHP out of a Blown 347


Oct 21, 2009
I'm going to be refreshing my stock 302 block. It's a 306 right now and has somewhat high compression (~9.5:1 to 10:1..not sure) and is bolted to a AOD Transmission. I want to reach the 425-475RWHP Range out of Stroking to a 347 and adding either a Turbo or a Supercharger. If I can do it without a supercharger/turbo then that would be good too. I'm looking to at least keep it at a boost friendly compression ratio and keep it on at least 91/93 octane gasoline. I do know the AOD is a power soaking transmission, but I want to keep it auto for more drivability and to maybe to take it to the track if I want to. Are there any suggestions of parts and stuff I should use in order to reach my goal?

Here's what I had written up, I dunno what I will achieve from it though...

Block: Ford 302 stroked/bored to 347 (All Forged Rotation Assembly with Dished Pistons)
Heads: Trickflow Twisted Wedge
Camshaft: Trickflow Stage 2 or 3
Intake Manifold: Trickflow Track Heat Upper/Lower
Compression Ratio: ~8.5:1 - 9:1
Turbo/Supercharger: 10-12 PSI
etc...if I left anything out...if not what should I be looking at?

I'm replacing pretty much everything including sensors and most of the wiring too..

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This last 25% is foreign territory at this point
Founding Member
Nov 29, 1999
Your list makes it sound so simple. Take your budget and double it, the AOD isn't an option, they suck, but an auto trans is fine.
Generally speaking to reach 500hp+ (crank) low compression+N/A isn't really a great choice (not that it can't be done) odds are you'll need to build a fairly high revving motor. You need to decide if your going to boost it BEFORE you buy internals/heads etc. I also think you should consider a custom grind cam if your looking to get the most from your setup.
do you have any experience building motors? Especially hi-po motors, as paying a shop to put this deal together is going to raise the cost significantly. It's all the machine work, nuts, bolts, and other little things that people just don't consider when they budget their project. If a budget isn't a concern for you then skip the 347 and go for a dart 408w+ hellion kit :nice:
An s-trim on top of an HCI 302 can get you into the 400 range but you'll have to consider the rest of your drivetrain. Trans won't hold up to that much power for long (t5s don't even like 225 crank :D) and you're not going anywhere on a worn out 20 year old rear end.

Just some things to think about