If you experience a miss fire or popping the jets are too small.Remember it's a 750 plus i've been told as much as 30 cfm with the choke horn removed,thats alot of air you will have to equalize the fuel mix to match it.I made that mistake of putting small jets in my 650 it missed and popped like crazy and i had to put a whole lot more jet in it than i figured.You will know after the first blast where your at,even if it sounds good still check the plugs and make sure it isn't lean.
jets dont mater on the engine size. they are only in relation to the cfm of the carb and then adjusted to get the correct air fuel ratio. the idea of puting smaller jets in big carb just becasue its on a small motor is really wrong and can be bad in that it results in a lean condition. the correct train of thought is to put a smaller carb on the smaller motor. so with your 750 i would put the orignal jet sizes that it came with back in to start with. on my motor a 302 with ported heads and a roller cam it has 600dp holey on it. i had it dyno tuned and it made 321 hp. The dyno operater made a jet change on the secondarys of 2 steps richer. he also noted that there was no vacume building in the inatake at the top of the power band indicating that the 600cfm is not to small of a carb. now this motor only spins up to 6000 rpm. Now i would sugest geting a smaller carb, aroun 650 cfm (gives you room to grow.) a smaller carb will have much beter throttle responce and drive alot smoother that the 750. oh and sory that this kinda sounds like a rant, its not susposed to be. my stroung suit is working on car not writing posts.
2 reasons I am using this big carb, and YES, I agree it is too big for my engine, so I am not arguing that point. 1) my 600 edelbrock could not keep up with my last engine. I "outgrew" it and needed something bigger. 2) got this one for $50 because a friend had it and wasn't using it. So, I couldn't pass up a $50 holley DP, even if it was a little too big. If I would have bought a new carb, I would have gotten the 670 cfm Street Avenger. I think I can make the 750 work for me, even if I lose a couple HPs from it...
My neighbor has a 770 SA on his truck with a mild 302 and it's stout! He lost power and throttle response when using my 600 for a while... which ran very strong on my stock 302 (4v and Tri-Ys only mods). On my 306 with single plane and fairly rad, it lost power with a 650 DP. Got my best performance with 700 and 750 DP. I understand a 600 might be just enough to feed a 302, but that doesn't necessarily make it the better choice. You got a 750, now make that sucker run! If you tune it just so, you won't see a throttle response improvement by switching down 100 cfm. You WILL however see a mid and top end loss! Sorry, you won't change my mind, and we will have to agree to disagree if you think 100 cfm added hurts anything. You gotta really think about how light our cars are. If a heavy, full size truck can run well with a 770, what would it do for throttle on a feather-weight like a Mav? Common sense.
What about a 1000+ cfm getting 16-17 mpg. You can make the carb work, it will just take some time spent reading and a few dollars more.
