Hello, I am in a dilemma, with the performance of my engine combo. Started with a 350/260hp GM crate motor. Installed a 17083226 Qjet standard adjustments ran fine. At that time I was going to build a short block and top with vortec heads, rv cam and such. Gathered up a lot of new parts, including low hour marine vortec heads, Pro Products Cyclone dual plane intake, roller rockers,beehive springs and retainers,seals and a comp cam x4262x rv type to keep the low end torque for towing.
The short block was bigger than my budget and I bought the crate motor. Time flies, started driving the crate in 2008! Now I have put the top end together, reverse waterpump,serpentine, real fan and standard rebuild on 17083226, idle adjust, fuel regulator and timing it runs pretty good, not great! Took to track 67 el camino, 10lbs in rear tires and it gripped pretty good. 1st pass OK, 2nd pass, I warmed the tires in the box, left hard and fell flat before an 1/8 mile! Tried to boost fuel, max 6psi , bad pump, replaced pump, same thing, removed filter, same but not every time, it's weird but I'm guessing it is carburetor. Normal driving is tolerable, so I dug out some carbs . I have a 7045228 but like the17083226 it is not set up for my combination.
Engine 350 gm
4 inch bore
3.48 stroke
CR 9.5-10:1
Vortec heads 65cc chamber
Cam x4262x
Lobe center 111
Center intake 107
Duration intake 262 exh 270
Duration @ .05 218. 226
Valve lift. intake .462 exh .48
Timing 12btdc
For starters I need to choose which of these would be the best fit for this and maybe a little more cam down the road.
Do not need 2 carbs for one motor, lol but surely do need help on this. I know plenty of those quadra junkers but I understand the wide range of adjustments that can be made to better tune than any other carburetor.
Sorry for the long winded post, I am anxious to get this dialed in. Thanks for input, to customize my rebuild. Judge
