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Discussion Starter #1
I am thinking about doing a head swap on a 283cui.I was thinking about having a set of 461 heads rebuilt or maybe going with a set of Vortecs.It currently has the small valve/small chamber Power pack heads on it now.This is a cruiser and i just want a little more pep any suggestions?
 

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I can't remember the exact size but the small bore of the 283 limits the intake valve size. The intake valve will hit the top of the cylinder. The cylinder wall has to be ground out for the bigger valve after a certain lift. A 2.02 with much lift won't work with out modifications. The larger valve is shrouded and really doesn't help much from what I have been told.
 

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IMO a basically stock 283 doesn't move enough air to benifit from a 461 head even if you modified it to work. The 461 was made for a 327 with some compression, a big camshaft and serious intake system. That's my opinion anyways.......LOL. RM
 

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The Vortec's don't work well in this application either. The 1.94 valves work fine in the 283 ( I run 2.02's in my 307 which is the same bore, I'm .060 over). The problem is that the chambers of the Vortecs will lower your compression th around 8:1 I believe. There are domed pistons for the 283, but they're designed for the old style combustion chamber. You could mill the Vortec's about .030 to get around 8.5:1, but that's getting close to the limit for flat milling the thin cast Vortec's. Your best bet would be to find a set of 58cc heads off a H.O.305 (Monte Carlo SS (84-87, Trans Am/Z-28 84-92). They;ll flow better than the heads you have now and should flow enough to support a 283 quite well. You could shave them enough to get around 9.5:1 compression.This would be a cost effective way to give your small engine a little more pep. Run a Performer intake with a small carb and you'll be find.
 

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I agree the 305 HO head with the 50 something CC chamber should give the 283 a little help but not the 461s. RM
 

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I agree with the previous statements about lost compression and valve interference (2.02 valves). I wouldn't screw around too much with that 283, you really have to work to make them run decent.

That being said, I've got a fresh set of 305 HO's in my garage:).....

Kev
 

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Discussion Starter #7
Thanks for the info guys.This car is only used for cruisin,so maybe it is best to leave well enough alone.
 
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