OLD Modified Corvettes

randy wilson · 12-18-2013, 05:23 PM

Joe, that was a great article at competition plus. Great article. But the similarities are close, but not the same. They had 4 manufacturers, with 4 totally different cylinder heads. Don't know about American motors, and mopar, but, for instance, I believe the head of choice for GM was the 461X. For Ford, it naturally would be the canted valve Cleveland. I'm a little familiar with both, and the X head flowed around 220 out of the box, and with a great valve job, and what matching was involved, never exceeded 240 cfm. The Cleveland, out of the box would go 285 cfm. I don't know what the mopar 18 degree stuff did. There in lies the problem. Brodix, if anyone cares to look, are as follows. (And I'm close here, not exact.) Chevy, 269 intake, 179 exhaust, Ford, 272 intake, 202 exhaust, Mopar, 270 intake 200 exhaust. That class would still be going today, if they had something like that. Just my opinion. If you let the Chevy use external port plates, 1\2 inch thick, with no internal mods, the exhaust flow goes up to close to 200 cfm.

12-18-2013, 05:23 PM	#11
randy wilson Senior Member Join Date: Jan 2007 Location: N/A Posts: 882 Likes: 0 Liked 22 Times in 22 Posts	Re: OLD Modified Corvettes Joe, that was a great article at competition plus. Great article. But the similarities are close, but not the same. They had 4 manufacturers, with 4 totally different cylinder heads. Don't know about American motors, and mopar, but, for instance, I believe the head of choice for GM was the 461X. For Ford, it naturally would be the canted valve Cleveland. I'm a little familiar with both, and the X head flowed around 220 out of the box, and with a great valve job, and what matching was involved, never exceeded 240 cfm. The Cleveland, out of the box would go 285 cfm. I don't know what the mopar 18 degree stuff did. There in lies the problem. Brodix, if anyone cares to look, are as follows. (And I'm close here, not exact.) Chevy, 269 intake, 179 exhaust, Ford, 272 intake, 202 exhaust, Mopar, 270 intake 200 exhaust. That class would still be going today, if they had something like that. Just my opinion. If you let the Chevy use external port plates, 1\2 inch thick, with no internal mods, the exhaust flow goes up to close to 200 cfm. __________________ don,t have one Last edited by randy wilson; 12-18-2013 at 05:27 PM.