Engine build help please

Limited Late model engine build advice needed; 350 SBC steel block/steel heads with flat top pistons, 3.48 crank, 10.5 compression, and 4 Bbl carb. 5.7 or 6 inch rods, and why?

Thanks in advance.

6", because it has less working angle as the crank rotates. Puts less pressure against the cylinder walls by being more straight up and down as it works. Also puts the pin higher in the piston which has benefits. We've run even longer than 6, but it's not as common so the price of pistons goes up considerably and there's not near as many options.

Thanks Basecircle; rules state 5.7 or 6" rods only.

the 6in rods also increases piston dwell , which benefits higher rpm engines , how ever a 5.7 will create more low rpm torque , i have seen both win races , i prefer the 6in on the chevy,s because most tracks are 3/8ths or longer that we race on. My ford all steel engines are 302 based 355cid with 5.4 rods and 1in CH pistons and they pull like a mule off the corner , but you have to coat the piston skirts well , which i would suggest doing on any piston.

This will be in a low RPM motor, there is a 6500 RPM rule

Your going to want it to pull harder . A 5.7 rod will help get some grunt out of it. It will also save you some weight to help it rev quicker. IMO the longer rod only benefits you if your going to turn the rpm up. My rule is below 7000 shorter rod .

Fastford how much do you turn your motor with this set up ?

rarely over 7500, with the correct cam , it will pull good to 7000 , but with flat tappets thats about it for usable power.

Rod length plays a bigger role on engines that are restricted. I know drag racers that believe all the rod does is hook the piston to the crank.I always go with a longer rod because I want a lite piston.

what tracks are runing this?

USRA Late models in midwest