WebImproved power throughout the rpm range with Speedmaster Cylinder Heads! Shop cast iron, aluminum, CNC-ported, CNC-profiled heads and more. ... Chevrolet Ford. Outlaw Series ... Competition-ready heads feature fully CNC machined combustion chambers and blended seats for increased air flow and well as revised exhaust valve angles for larger ... WebFeb 23, 2024 · Those heads are old smogger type and most of them all flowed really close to each other Usually in the low 200's like 205 cfm and exhaust side in the 145 area. …
Stan Weiss
WebThe consensus is that with proper porting the oval port heads can flow just a well at above 4000 RPM as the rectangular without losing the middle and lower-end performance. ... Chevrolet Big Block Head Casting Numbers. Casting numbers are found under the valve cover. Casting No. Year: Engine Size: CC: HP: Port Type: Chamber: Intake Valve ... WebOct 12, 2014 · P.S. The 186's (2.020" valves) flow 220/142 @ .500", the intake's hold there, the exhaust's go slightly higher and flow about 145 @ .600". These are all "nominal" numbers on unported heads. The best "production-line" heads Chevy ever had (years ago) were the earlier (Fuelies) 461X's. We used/supplied many of these on some early C … djhdb
Chevrolet Big Block Heads - Casting Numbers and Specifications
WebDec 25, 2024 · Not surprisingly, the 799 heads flowed the most, with a peak flow of 250.2 cfm at 0.700-inch lift. The 706 heads offered the lowest peak flow, checking in with a maximum of 237.1 cfm. See... WebDec 28, 2005 · The 487 heads will flow as well as any factory double hump head. The only real problem with them is that they have poor combustion and burn characteristics … WebOct 14, 2005 · 3963512 454 70 Chevelle LS6, 450 HP. 3963512 454 70-71 Pass, Chevelle, Monte Carlo. 3963512 454 71 Corvette 365,425 HP. MY HEADS. 343772 366-454 76-84 Truck HD Oval Port. I dont have any other information on the setup. It's been rebuilt and I was told it had 10.5 :1 compression, but I think I'm going to have to pull it apart to see … dj hdj-x5bt