This is not a spread bore but look anyway just for the RPM specs and the price.
Now the story with it ..I got one for my Home ported 906 vortec heads.
I did cut the divider down about 1/2" that was it.
357" SBC flat top engine .005 piston down the hole 5.5cc reliefs .039" head gasket.
Cam is a Hydraulic Roller [email protected]
.50 and .492" lift, 110 LSA 1.5 stainless roller rockers 7/16 studs.
Beehive springs, 313 rate, 130 seat pressure.
It revs quick to 7000 rpm.
I ran a much modified 4779 on it and stock late 70's HEI distributor.
I do not like a flat floor in an intake manifold..I want it to have ribs "waffled" floor.
Find one in a spread bore and cut the divider a bit and never mind that the RPM rating is 5500.
Or run an adapter plate if you have clearance.
I assume you do not have the clearance.
I tested a ported Q jet intake against the Edelbrock Performer RPM intake. The GM q jet intake made 10 HP less than the RPM at the wheels.
It made best HP with a Q jet carb..I also tested my Modified 4779 Which made 10 HP less ..And I tried the Q jet on the RPM intake and on it vs the 4779 the Q jet now made 10 HP less.
I also tried a marine Q jet intake and it made 30 HP less than the RPM intake.
The plenum ported Q jet intake was worth 20 HP over the marine.
All of them would pull all the way to 6500 rpm without nosing over.