[performerrpm]

Originally Posted by Steve C.

Dyno testing Ported 6X Heads and Edelbrock D-port Heads

Engine Displacement: 467 ci
Bore/Stroke: 4.185 / 4.250-in
Comp Cams Xtreme Energy hydraulic roller
Duration At 0.050: 224/230-deg

6X - 550 ft.lbs. Tq at 3600 rpm / 492 hp at 5100 rpm

Edelbrock - 570.7 ft.lbs. Tq at 3500 rpm / 502 hp at 5000

.

thats the xr276 hr isnt it? lol i had that cam but thought it might be a touch small on my 467...thats pretty impressive with the 6x4s....im guessing no port work on d port edelbrocks?

[Steve C.]

Yes, tested the out-of-the-box Edelbrock castings. I presume it was the XE cam.

I added the link to the article in my post above.

A fwiw tidbit....
Many years ago my previous engine builder put together a 4.250 stroke for a friend using the Edelbrock round port 215cc runner volume heads.. No port work other than a cleanup.
Performer RPM intake with a vacuum secondary 750 Holley and headers. Cam was a small Crower HFT with 236 degrees intake duration.
On the dyno at the start of the pull it made 499.4 ft.lbs. torque at 3400 rpm.
At peak tq rpm it was 570.7 ft.lbs. and carried over 500 ft.lbs up to 5300 rpm.