Stock internal 318 redline??

A good thing about smaller engines they tend not to fall off as quick after peak hp probably cause it's easier to fill there cylinders cause displacement size and heads available.

Here's similar engine to the OP stock 318 low cr long block xe262h cam 4bbl headers peaks at 5000 rpm with 282hp and makes over 270hp from 4500-5500 rpm, shift 1-2 from 5000 rpm drops to 2950 rpm and a shift 1-2 from 5500 rpm drops to 3250 rpm, engine makes 192 hp at 3000 rpm and 227 hp at 3500 rpm.

318 Long Block Bolt Ons - Tech Articles - Mopar Muscle Magazine