motor combo help

[megaladon6]

just as a double check, what oil pan is it?
regardless you should be fine, 7qts is about 2 over stock. plus i don't think they make a 7qt w/out a deep sump, just make sure the pickup clearance is correct.
also, when you use nitrous you need to make sure that there's extra fuel available. honestly i don't know what that takes on a carb, since it's not a constant use thing.

 

[81elcamino]

its the summit 7 qt and pump combo, its all the right clearence and everything, yea i know bout the extra fuel, thats all plumped already from the last engine. thanks

 

[1981elky]

ive got an 81 elcamino. 355 12:1 custom roller cam. gutted double humps. 1.6 roller rockers and stud griddles. victor jr intake. 650 double pumer. holley blue fuel pump. th350 w/ 3000 stall. big tube headers 3in exhaust. and 3.73 with posi. went 11.30s on motor

 

[84sbcregal23deg]

for choosing carb size, its more about the engine size and RPM. 850 would be way to big, the right way to figure it out would be to use this equation. rec. carb CFM= cubic inch displacement x max RPM/3456 x volumetric efficiency. from the parts you've listed, your VE should be around 85%-90%, which is pretty efficient for a street car. so it would be 388 X say 6500 (powers only gonna drop off from there)/ 3456 X 88% VE. this will come out to be 642.17 CFM of air at 6500 RPM. so in theory, 650 double pumper is what you need! 🙂 most people think bigger is better, i can attest from my personal experience that theory is not always true. my setup last year was very similiar to yours, and i tried both a 750 DP and a 650 DP, only to find it was more drivable, snappier and faster up top 😱 with the 650.