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Discussion Starter · #1 ·
I have a 454 30 over that i want to make 500 hp on pump gas, im good around cars but when it came to figuring out what kind of heads, cam, intake and carb to run im lost. I really get lost when i start reading about head flow numbers, i have read the 781 or 049 heads would be a good place to start but dont know of any machine shop that will re work them and if i do take them to get re worked dont know what to look for in a good job. In other words they could tell me they did the hole 9 and i wouldnt know if they did or didnt. Anyone have a good combo running the 781 or 049 to make 500hp, part #'s would be great and maybe the name of a good machine shop thats honest in the dallas/fort worth area

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I ran a DynoSim on a BBC where I put together parts for a cheapo grunt motor and posted it here the other day. I built it as a 505 just because more cubic inches are easier to make power with than fewer cubic inches, but included into the thread, the caveat that if you wanted to use a standard production 454 or 427 block, you could just use 6.135" rods and forget the spacer plates. Here's a link to the thread....

Now, here's my best advice about the heads. When you can buy excellent aftermarket heads these days for relatively cheap, it makes little sense to start with production heads and spend all the money to bring them into spec on the guides, valves, springs, magnaflux, yada, yada, yada when you can buy and use aftermarket heads right out of the box that will flow better in the first place and for very little more money after you add up what machine shop prices are these days.

If you have any interest in building the 505, read through the entire thread, because I came up with some 6.535" Chinese rods from ebay that might work well in this rpm-limited build (after some enlightenment from Guy Hiltz) :thumbup:

Anyway, bottom line with 4.030" bore, stock 454 4.000" stroke crank, these heads, retro-fit hydraulic roller cam (I used a CompCams 11-433-8, but you could use another grinders cam with the same timing figures), intake and carb that I used in the build (RPM or Stealth mounting an 850), using standard length 6.135" rods and no spacer plates and anybody's 454 pistons with a 0.250" dome, here is the result....
2000 174 457
2500 221 465
3000 284 496
3500 358 538
4000 431 566
4500 491 573
5000 534 561
5500 558 533
6000 547 479
Peak volumetric efficiency 101.1% @5000
Peak BMEP 187.8 @4500

I'm confident that these numbers are real, particularly since I factored the published head flow numbers from the manufacturer by 0.90 before I ran the Sim.

I don't have time right now, but later I'll check out RHS heads with smaller chambers and maybe flat-top pistons to achieve roughly the same results.
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