^^^x2. You've spent all this time diagnosing and troubleshooting, maybe it's time for the carb swap. If it fixes it, then that's that. If not, put the other carb back on and keep moving, but at least you've eliminated another step either way.

 

 

Old carb is off, have the intake riser cleaned up, any general consensus as to the use of some type of sealer on the carb to intake gasket or leave dry? If life allows , new carb should be installed in the next couple days. Mid 60's for one day next week....hmmmmmmmmm

 

No sealer

 

Thank you!

 

Carb swap fixed the issue. Back up and running. Fine tuning to do yet. I know the steps, a question- what would you all/ any of you suspect would need to be tweaked moving up 200 cfm aside from the carb settings, timing? dwell?

 

Dwell is not related to carburetor change and should remain at the factory recommended 30 degrees. If you had a good tune with the previous carb, timing should not require any change. All you should have to work on is carburetor tuning.

 

quick update- Fine tuned the carb with vacuum gauge. VERY happy with Holley Street Avenger 870, all it took was 1/2 turn or so out to richen the mixture and everything else was factory set and spot on it appears. I can tell the new, larger carb gave me a boost. Car screams through all gears, no hesitation nothing, also hooked up my kick down for the first time in awhile. boy does it turn heads if I goose the pedal a bit, I have to be careful taking off, she wants to fly! Awesome throttle response.
As i have mentioned, I have never messed around / tore down a carb. Would the old Holley I removed be a good first try???

 

Yes. Very simple carb to rebuild.

 

Great! I'll get a rebuild kit and give it a try. Do the kits come with instructions or is there a good book to check out?

 

Lots good books on holley out there. I have a few will check later.