adapt thermo to rpm

[B.Tallent]

hi everyone, here's whats going on. finishing up my 31 Ply. coupe with a 69 340/ 904 combo. switched to a edelb. rpm manifold and want to run a thermoquad. I have a 1" spacer/ adapter but dont like it and will have to blend the ports and center divider ( probably will, any way I go ). what In all your collective wisdom have all YOU guys tried or what is better for adapters for this combo. I have a newer style afb carter 625 that I will do the cam break in with but really have my heart set on the thermo. thanx, Brian

[dodger1]

Other than cutting and welding a spreadbore flange from another aluminum manifold, I think you're stuck with the adapter. Or, swap the Ed. for a Weiand - there's a moderately high-rise model with the spreadbore pattern.
Sounds like a nice all-Mopar project. Any pics?

[pcrmike]

I will be looking for a square RPM airgap. Is that what you have, or a regular RPM?

[B.Tallent]

hey Dodger, I'll get some pics posted, guess I need to learn how. PCR , it's just the regular RPM. didn't think I needed the air gap for a nice cruiser. thanx

[pcrmike]

You didn't, but I was just wondering. I am going to built a strip monster and was looking for one. Not too seriously yet, but in the next few months. Time to build one for me now.

[bulldog426]

i have used the mr gasket brand adapter before it just looks like a regular carb spacer, you can pick em up at the local advance or autozone for around 20 bucks, if the guy at the parts store knows what the heck you are talking about, they should be at the aftermarket carb display where they have the holleys and edelbrocks and a few other carb accessories..

[B.Tallent]

actually what I was wondering is, what would work best for a street engine using the performer RPM i.e;an open design spacer which would allow both sides of the manifold pulse to be diluted, or a four hole to keep each side separate and better response from the thermo-q . I have seen performers with the divider wall cut out a little so I assume that some pulse dilution is necessary. my concern with this is will the open hole cause me problems with low end torque on the street or will I not notice because it is a street motor. thanx

[pcrmike]

On a moderately built 360, I noticed a drop in tq using an open spacer plate on one, and after going to a four hole spacer, it was stronger. On that mani with an eddy carb, that was my experience, however that was in a heavy one ton.