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Discussion Starter · #1 · (Edited)
hey guys,

Im building a Mark IV 454 bored .030, hypo -12cc domed pistons, forged crank
motor,

I have the opportunity to buy some 781 casting number heads that have been recently rebuilt according to the guy selling them.

he's asking 600 for the heads and a edelbrock intake
is this a good price?

and would they be good for my setup?
Thanks for your help
JR
 

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Discussion Starter · #2 ·
forgot to add, this will be a street/strip application. I am aiming for a CR of 9.5 to 10:1. I am trying to get it around the 500HP range. do you think this is possible?
 

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Discussion Starter · #3 ·
thanks alot for your input. yeah I figured I would need 108cc to 110cc chamber, but I wasn't sure what the 781's were, i'll pass on them, maybe I'll just wait and save for some new aluminum heads!!

Thanks again.
 

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Hey jr 2009 im building a similar mill let me know how goes it i have the 781 heads as well and wanted to run em but the 400 h.p. 500 ft lb goal is right in there for me (going in a 3/4 ton 2wd p/u)
 

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Be careful when using dome pistons (designed for open chamber heads) with close chamber heads.

820's heads work nicely on a 454. these heads came on early 70's 396 and 402's. 112cc semi open chambers with a very good I/E ratio. should make 9.33:1 cr assuming a 0.040" head gasket and a 0.015" deck.

A BBC with that compression (9.3), can run a cam with 220 to 230 degrees duration at 0.050" (a compcam 270 or 280) and make 450 to 475 hp.

zero deck the block, a use a 0.025" head gasket and cr will climb to 10:1 cr. This compression will support a compcam 292H (244/244 at 0.050") and make 500hp.

500hp requires a head that flows 250cfm. a stock 820 or 781 or 049 will flow that much if the lift is over 0.500". Bigger valves would also help.

use a edelbrock RPM intake or victor jr. 850cfm carb would be best.
 
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