[dlw6767]

i just bought a 65 gto with a 68 motor in it, car came from west coast. has pontiac cast intake with a carter afb carb,no numbers but looks like new. in between the two air mixtures is a big screw,another pre set air mixture i beleive. the ful inlet is on drivers side,the choke is a heated tube type. i do have a pic of carb. heres the problem, whoever put this together had the vacum advance hose hooked up to full vacum on the carb, it doesnt have a ported line otherwise the carb would be good. ive cked edelbroke performer carbs,they do have ported lines, but all are electric choke and the fuel inlet is on the other side. are the thunder series carbs fuel inlets reversable? should i get a 650 or 750 series? i suppose i could keep the carb and put a mecanical dist in but it has a brand new vacum dist in now. it looks more period correct now. any advice, thanks. ill

[gtome]

I run mine with manifold vac....is there a reason you cant?
The fuel inlet could probly be loosened and turned to the other side (flanged?)if that is what you are after.

I dont think many here are having much luck with the Edelbrock carbs, Qjet and Holley seem to be the most dominant. Never tried one myself.

If that carb is in good shape I would just find a way to make it work. Also we would need way more info on the engine than the year to recommend a size for you. Heres a calc for you to try. http://www.wallaceracing.com/intakecfm.php

[aldbeir]

in cliff ruggles quadrajet book on pages 49 50. he discusses manifold vs ported vacuum. it basically says unless you are running at idle all the time the vacuum is the same.once the timed vacuum is exposed to vacuum i.e. off idle. manifold and ported are the same.a problem can result when running a large cam with an auto trans on manifold vacuum. rpm drop when the car is put in gear will change timing

[dlw6767]

thanks for the info guys. i did find that this is the orginal style carb for the car so im going to keep it. ill try the manifold vacum again to see if that works right. the dist is new, could it be the vacum part pulls open to soon,isnt their diff vacum pulls?

[gtome]

It could be, but I would suspect too light of mech advance springs first if you are getting too much advance too soon. You never really said what the problem is though?
I would unhook the vac advance and plug the carb end, check your timing (should be 12-16), run the rpm's up to 3000 or so and check the timing again (should be 32-36). You can watch the mech advancing while raising the rpms's, and can be all in (to the 32-36) at as low as 1800 rpm or so. Then hook up your vac advance and you should be fine. Vac advance can take the timing as high as 50 or more.
And if you have an adjustable vac can, the spring rate can be changed to limit the amount of vac to it (essentually the same as going to ported vac).

[dlw6767]

i installed a accel adjustable vacum advance, made some timing adjustments, adjusted the vacum advance, way better now! feels like 340 ponies now.

[gtome]

Awesome! Keep your eye on the adjustable vac advance. I have read that it may creep around on ya.