my buddy has a pair of 215s on his cast crank 347. on motor through the 4150 and victor jr it runs 6.70s@101 in the 1/8 mile. we are hoping colder weather and some tuning will get it into the 6.60s. if the 215s are any indication, the 200s should be good to go. i prefer the TFS heads, but the RHS heads are have been proven to run good.