I had a 65 GS 3 speed car with oem carb. It was ok with the stock carb but when I switched it out for a Edelbrock 750 AFB it really woke it up. It was like a totally different car.
I know Matt's rep has sure been declining fast lately. When I joined here I thought he was the Nailhead king. A while back I posted about my 66 GS and it not running well on a hot day but pretty strong when cold out. I messaged Matt years ago about it and he told me his builds ran just as strong in 100+ degree temp. Not wanting to gossip but he has to be kidding me.. Your mid 12 second 1/4 mile Nailhead speaks for itself.. I was just trying to see if the Q-Jet manifold itself flowed better.. It's been over 30 years since I drove my 66GS and to this day I still bum out that on the day I sold it I found out I was only running a 500 CFM AFB for 8 years..
let's say I go the modify (DOC's) the square bore / AVS 800 carb path. With my 66 GS. I currently have a ST400 Trans I'll need the microswitch and new air cleaner or air cleaner adapter? Also need a Throttle linkage change/adjustment? Or will the old Air cleaner be too small or have hood clearance issues?
You won't have to modify the throttle linkage. And they make universal electric switches for the kickdown. You probably have to put the switch pitch on a toggle switch or something like that.
the 800 cfm lowered throttle responds and low end power and might have helped a little after 5000 rpms. that was on a built 425 even. Greg Gessler flowed the square bore vs the q-jet and was no difference in air flow i posted the sheets before on here. stock air cleaner would work but you need more air flow with a little taller air filter that keeps the top open a little and some holes drilled on the bottom. what micro switch do you need the one that goes on the back of the throttle linkage for the idle ? ps unless you can get a q-jet intake with a rebuilt q-jet carb that came on a switch pitch car. for a decent price.
I have a Quadrajet setup for a '66 Electra and it had a switch-pitch. It is possible that a switch-pitch switch (say that three times fast) from a non-Quadrajet car will not work properly, but there was a factory switch for the Quad.
I just reread this thread; someone suggested a 750 Edelbrock rather then working with a 55 year-old Quadrajet. Maybe, maybe not. I bought a 650 Edelbrock new for the Buchev (yup, I shoulda gotten a 750, but I'm slowly putting a set of factory dual quads together) and I have had nothing but trouble with it. I finally got so sick of pulling it apart and having it run well for two or three days that I put it back in the same used ziplock bag that held a grubby old Edelbrock that I had pulled off a small block Chevy that I was getting rid of. That dirty old Edelbrock has run beautifully in the Buchev for years now. Go figure.
John your saying the new Edelbrock 650 is junk and the old edelbrock is good?? What is a Buchev? So I should get a Quadrajet or find a dirty edlebrock? If I buy an Edelbrock 750 or 800??, will modify the intake anyway...
I have a '66 quadrajet carb and manifold that came on my '66 425, but as I recall it is not the correct carb number for that application. I am not saying that the new Edelbrock is junk. I have had the Buchev for about 12 years and bought the new Edelbrock when I was installing the engine. I am saying that my particular Edelbrock carburetor is junk, but it's probably a 4:30 PM Friday carb. My grubby old one is definitely not junk. Before Tom T chimes in and reminds me that he did rebuild the old Edelbrock when he redid the engine after someone else screwed it up royally, I felt that the old Edelbrock ran satisfactorily before Tom's rebuild, but Tom wanted me to start with a complete rebuilt engine, and I agree.
