In 2 cases I pulled a Comp Cams solid roller cam from customers engine and installed a Racer Brown STX-22 SFT cam. 1 was a small block 408 and the other was a big block 512. Both were low 10 second cars and ran some high 9s with the flat tappet. One has since switched back to roller and runs exactly the same, no gain over the SFT. My Demon also has a STX-22 and has gone in the 9.60s. Stroker small block with production iron heads. 2150+ passes with only 2 spring changes, 995-16 comp. $100 a set. Also my lebaron has the same STX-22 cam in a 512 BBM with Indy SR heads. 1300 passes with 1 spring change 928-16 comp. $150 a set. Been 5.40s 1/8th mile and 8.50s 1/4 mile.