Not to steal from the other fine thread, but how would/has AFR
done when someone just R&R'd a set of stock heads, such as an LT1/LT4, then ran it at the track.
Just curious, as porting really shows talents of the porter.
I would rather see talents of the designer.
For Example, lloyd elliots LT4 heads against AFR CNC heads. and this can go on forever.

I would expect the AFR heads to flat out NUKE the best ported LT1 OEM head. The ports are just better designed on the AFR heads.

It would be a slaughter.

I would love to see a before factory vs a LLoyd ported and a CNC ported AFR.

LT1 Cylinder Head Comparison - LT1 Head Shootout!

POWER OUTPUT
AFR AFR DART DART EDELBROCK EDELBROCK GOLEN GOLEN TRICKFLOW TRICKFLOW
RPM HP TQ HP TQ HP TQ HP TQ HP TQ
3,000 256.2 445.1 248.9 434.1 256.5 442.1 252.8 440.7
3,100 262.7 445.5 256.4 434.6 260.4 442.5 258.1 438.4
3,200 271.9 446.4 264.1 433.6 263.6 435.9 269.5 442.5 266.9 438.5
3,300 280.8 446.8 272.2 433.5 273.1 434.8 279.2 444.3 276.6 440.2
3,400 289.3 446.9 281.5 434.8 281.9 435.7 288.7 446.1 285.4 441
3,500 298.6 448.1 290 435.2 292.1 438.3 298.5 447.8 294.1 441.2
3,600 307.8 449.1 298.9 436.2 302.4 441.2 307.1 448.3 303.6 442.9
3,700 318.5 452.2 308.7 438.7 311.2 441.9 318 451.4 314 445.8
3,800 329.3 455.1 318.4 440.1 321.8 444.9 328.5 454 324.8 448.8
3,900 338 455.3 328.3 442.2 332.3 447.6 338.2 455.4 334.8 450.9
4,000 348.2 457.2 338.3 444.3 342 449 348.6 457.8 344.9 452.7
4,100 358.1 458.8 349.6 447.9 351.4 450.3 359.5 460.6 355 424.9
4,200 368.9 461.4 361.7 452.3 361.1 451.6 371.1 464.2 366 457.7
4,300 381.2 465.7 374 456.8 370.5 452.6 383 467 378.5 462.3
4,400 393.9 470.1 385.6 460.3 380.3 454 395 471.3 391.2 466.8
4,500 405.2 472.9 395.9 462.1 390.2 455.4 405.8 473.5 403.1 470.3
4,600 416.6 475.6 406 463.5 400 456.7 416.4 475.4 414.6 473.2
4,700 427.4 477.5 415.7 464.5 409.5 457.6 426.5 476.5 425.7 475.6
4,800 436.9 478 424.5 464.4 418.1 457.5 434.8 475.7 435.4 476.6
4,900 445 477 432 463 424.7 455.3 441.1 472.9 443.7 475.7
5,000 451.7 474.4 437.8 460 429.9 451.6 444.3 466.7 450.3 472.9
5,100 457.3 471 441.2 454.4 434.6 447.6 445.3 458.6 453.6 467.1
5,200 463.7 468.4 443.6 448 439.4 443.9 447.6 452.2 458.9 463.6
5,300 471.3 467.1 449 445.1 445.1 441.1 455.8 451.9 468.3 464.3
5,400 479.7 466.6 457.2 444.8 452 439.7 467.3 454.6 478.7 465.8
5,500 486.4 464.5 464.7 443.8 459.1 438.4 476.6 455 477.4 466.4
5,600 492.5 461.8 470.6 441.7 465 436 482.3 452.3 495.7 464.9
5,700 498.9 459.7 476.8 439 469.1 432.2 485.2 447 500.2 460.8
5,800 504.6 456.9 481.4 435.9 472.2 427.6 486.3 440.4 502.3 454.8
5,900 509.7 463.6 483.5 430.4 472.9 421 490.1 436.3 505 449.6
6,000 514.4 450.1 480.5 420.5 471.8 413 493 431.4 508.6 445.2
6,100 514.6 445.6 510.2 439.3
6,200 516.3 437.3 511.5 433.3
6,300 511.9 426.9 511.1 455.9
6,400 506 415.4
6,500 500.5 404.5

http://www.gmhightechperformance.com/ ... ead_comparison/index.html

I know it's not on a track however the difference between these heads is ALOT less than what some who are trying to sell them to you would like you to believe.

There is really no difference till about 5000 rpm. I am there all day at that rpm, not. Interesting nonetheless.
I am sure tuning etc could have made some more differences.
But look at Golen vs AFR up to 4900 rpm. Interesting, then at 5000 rpm the extra air flow showed its capability.
Unless another article can show more tuning with each set up, I will stick with my CNCinc heads from Florida, circa 2001.

Steve I'm running the same CNC Cylinder Heads ported stock heads, one of Pete's custom grind camshafts (224/230 605/622 112), and the stock LT1 shortblock. My M6 car will consistantly trap 119 mph. So, it looks like to me that our heads are at least comparable to even the best aftermarket heads.

I am with you on that.I am running an XE 230/236 with 544/555 in my 396 auto, and trap 119 also.
I have been told our heads were real good in their day, but the exhaust wasnt as good as say, an LPE heads exhaust.\

From what I've heard and read the LT1/LT4 heads, when ported, are very good. If you were asking about the L98 113 casting heads I have some experience there, and I can tell you that as soon as the long tube runner intake and restrictive exhaust manifolds and exhaust system is gone, the heads become restrictive, even when ported and bigger valves are installed. Then the bigger the cam you are running the more restrictive they are. There are huge gains to be had with a head swap on an L98 once you get the stock intake and exhaust in the dumpster.

What sold wasn't the intake flow, so much as the exhaust.