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SOme more 351m/400 Info.

TexasNomad

FTFS Designated DRINKER!
I want some thing I can run 87 on :D i'm cheap :p
 
Do you know whats so great about the Aus heads?
I hear allot noise about them online but never really what makes them so much better then other brands?

Aussie heads are just stock iron heads from a 302c from austrilia. They are just 2v heads with closed chambers. The closed chambers, with the correct pistons (.035-.055" of clearence), will create quench(turbulence actually) which does a better job atomizing the fuel and will let you run higher dynamic compression ratio without needing a better grade fuel, and still making more power. The stock 2 barrel cleveland heads are prone to detonation and that IMO is there biggest downfall.
 

TexasNomad

FTFS Designated DRINKER!
Aussie heads are just stock iron heads from a 302c from austrilia. They are just 2v heads with closed chambers. The closed chambers, with the correct pistons (.035-.055" of clearence), will create quench(turbulence actually) which does a better job atomizing the fuel and will let you run higher dynamic compression ratio without needing a better grade fuel, and still making more power. The stock 2 barrel cleveland heads are prone to detonation and that IMO is there biggest downfall.
thanks JB!
But kind of compressing are you running in your engine?
And any idea of what kinda of numbers it might be making?
 
9.7-9.8:1.. i changed to a different head gasket so i dont know for sure this time. i would expect an easy 425 but more wouldn't surprise me... not bad for a 400 with a hyd. cam, vacuum secondary carb and pump gas...
 

havi

third member
Aussie heads also don't have the thermactor bump.

Also, it appears the stock 351M/400 intake has enough meat you could mill it out to accept a 4bbl.

I've been pondering this approach:

Offset grind 400 crank + .095 to late 300 rod pin size about $200
Set of reconditioned 300 rods about $250
Mill cheeks to width on a set of late 300 rods about $150
Use 351M pistons in your rebuild instead of 400's no additional cost

With a .040 overbore, this nets 429.6 cubic inches.
With stock heads this will give about an 8.9:1 compression ratio(scientific guess)
With stock heads milled .040, this gives about 9.2:1 compression ratio.

With stock bore this is right at 421 cubic inches.
 

havi

third member
double post. But I'll add that I plan on going the TMI route for my 400, and the spare 351M block will be an experiment with the set-up I posted.
 
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Nice idea, the stock intake works as a 4bbl setup, i experimented on it and ran my 400 with it , it did a good job, Although i made a single big hole in it and made it to be a single plane small port manifold , it did a great job on low and mid rpm adn havent noticed the difference with my resently aquired weiand...
 

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