Here's an addition. I too have a 350 with 4226 world heads. Has alum dualplane,headers, 600ed carb. I too am changing cams. Check out the dyno charts on the comp website. The 262 non roller out dynos most all of the other grinds including rollers to about 280s. Also check out the vacuums @850rpm. Interesting results from the source-comp. I might add that have a .620 hyd roller in my ford and it rocks to 6k. Am surprised a small cam works so well with the sr head.