Thanks for the input. I kind of thought it wouldn't help me gain much torque by adding the new manifolds. I will probably go with my Iron-B intake.

It seems to me that low speed torque is the desired characteristic considering that this is a 3/4 ton 4 wheel drive Pickup truck with lots of rotating and static inertia. The larger runners of the 2 after market manifolds will not help low speed torque and it is likely that the higher velocity in smaller runners of the B manifold will be more suited to this app. The BT also cuts away some of the center divider which raises peak power but lowers low speed smooth-running and torque. The lighter weight of the aftermarket manifolds isn't much of a consideration. If it were mine to do I would use an Iron B and port out the undercarb plenum but leave the center divider intact. A 1" 4 hole spacer and small 4 bbl would top it off. It might even be a good place for a Iron A manifold which would be almost free, ported as for the B

Doug T

The Highlands, Louisville, Ky.

Try a bit more initial timing while you're at it, just remember to change the advance plate so you don't wind up with too much total timing. Do a search on this site and you'll find a number of articles/ questions and answers on how to do this.   

Frank/Rebop

Bristol, In ( by Elkhart) 

IMO (others may say different) advance the cam about 6-8 degrees and add a 4 hole 1" spacer and your low end torque will noticeably improve. Will be a little hard to tell with 4.56's unless you are going with a pretty tall tire. The truck will definatley jump right at the crack of the throttle.........All my close to stock street cars have had the cam advanced. It usually kills power over 4500 but on the street  I am never there anyway........Good Luck

56 Vic, B'Ville 200 MPH Club Member, So Cal.

From a couple of Dyno tests I've seen in the past, for your truck application, I doubt the Blue Thunder will be better than a "B" intake for low end torque. It showed somewhat weak at lower RPM on smaller engines also.

Paul

I dyno tested a close to stock 292 with the B intake and the Blue Thunder.. Blue Thunder was good for about 15 horse over the B.. That was with headers.. Probably not much gain through stock ex manifolds. I don't recall off hand the torque comparison, it was better, but most of the hp gain came from pulling a few extra rpm with the BT manifold



I would expect a Mummert to perfrom as well or better

I have a 1960 ford 3/4 ton 4x4 with 4.56 stock gears. Building a 312 for fun. Pondering the Blue Thunder or Mummert's intake over the cast ECZ-B 4 barrel. Would there be a significant increase in torque? Specs for the 312 build will be .040 over, flat top pistons, C!TE rods, stock G heads, dual ramhorn exhausts. Appreciate input.