489 build sheet?
Yesterday | 11:02 AM
#11
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Joined: Jul 2024
Posts: 189
Likes: 79
The 781 and 049 heads are grear performers for sure.
290 alum heads with 2.250" valves are way too big for most marine perf engines...but they flow well to male up for it. Some epoxy on the port floor would really wake them up. One ofntheblarger issues is that you can't really put a 2.19 valve in them.
The AFR 265s are an amazing option.
Great numbers on the 496 and iron ovals. What RPM did you turn?
Have you seen Vortec Pro's 781 and PP head results?
The 088 head exh port is worse than the oval heads.
Oddly...the L29 Vortec exh port may be the best factory BBC port ever cast. Small and fast..with a D port short side setup.
290 alum heads with 2.250" valves are way too big for most marine perf engines...but they flow well to male up for it. Some epoxy on the port floor would really wake them up. One ofntheblarger issues is that you can't really put a 2.19 valve in them.
The AFR 265s are an amazing option.
Great numbers on the 496 and iron ovals. What RPM did you turn?
Have you seen Vortec Pro's 781 and PP head results?
The 088 head exh port is worse than the oval heads.
Oddly...the L29 Vortec exh port may be the best factory BBC port ever cast. Small and fast..with a D port short side setup.
Yesterday | 11:12 AM
#12
Registered
Joined: Jul 2024
Posts: 189
Likes: 79
Here is the 2nd set of 781 heads i ever ported. I have the on the bench waiting to go on another 496 for my truck.
these flowed 311 on intake at 600.
Exhaust flow was 232 at 600 lift
I like looking at 400 lift numbers. These heads flowed 272 at 400 in intake and 187 on exhaust. This is very stout 400 numbers for a production iron head. Years ago I did a ported set of peanut port heads with a 2.25 intake. Never flowed them but the 489 inch truck motor put out over 650 torque and still did 511hp at 5200. Torque peak was at 3900. Stroub hydro roller.
these flowed 311 on intake at 600.
Exhaust flow was 232 at 600 lift
I like looking at 400 lift numbers. These heads flowed 272 at 400 in intake and 187 on exhaust. This is very stout 400 numbers for a production iron head. Years ago I did a ported set of peanut port heads with a 2.25 intake. Never flowed them but the 489 inch truck motor put out over 650 torque and still did 511hp at 5200. Torque peak was at 3900. Stroub hydro roller.
Last edited by hpmaniac; Yesterday at 02:13 PM.
