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I've been thinking about scrounging up a set of Aussie 2v heads, and having them cut for 4v valves. Any input on the subject? I tried a similar mod with an old set of 429 DOVE heads and CJ valves with pleasing results. Actually, I'd just use the old 429, but it's waaaay too much weight for the front end of my '68 Cougar. I want to go in more than just a straight line....lol I've decided on a 351 this time.
 
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Yeah. But an aussie would be best down low and in the mid range with the small ports. So why would you use large valves better suited for high rpm? Alot of Ford magazines have tested this without success. The larger valves would kill your bottom end. Unless yoour planning on taking it past 6k, which would be pointless unless doing circle track where 4v's arent allowed.
 

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The larger valve in the American 2V makes for a great low compression head, in fact last time I looked, the larger valve in the 2V head was the BEST flowing of all the C head setups. However, the AUSSIE heads have REALLY small chambers (58cc) and to stick the larger valves in them would cause them to be TREMENDOUSLY shrouded. I wouldn't do it without seriously opening up the chambers on an Aussie; when I do my Aussies I'm just getting a set of Ferra SS's that are the stock 2V and use them, when I asked the machine shop about the bigger valves they told me the could do it, but it honestly wouldn't make a HUGE difference and it would cost more. SOOOO.......
 

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I'm considering picking up a set of US 2V heads to play with....

The exhaust flow seems to need to catch up...the intake hits near max flow by .300 lift; the exhaust gradually builds up, almost catching up at .600 lift

Racer Walsh in Jacksonville Fl has 1.80" exhaust valves.....I may use them in the open chambered US heads with a little throat opening.....

Seems to me getting the exhaust to catch up sooner is MUCH more important than more flow in the intake side!

As for the compression thing, 9:1 is pretty sufficient with modern cams from what Ive read....maybe the efficiency of quench heads would make the power difference substantial, but if I wanted to take that step, I'd go balls out and buy yates heads off egay!!
 
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