an e cam and 1.7's w/ the .498 lift i believe runs into clearence issues... however someone at the track had a .512 F cam and they said they were cleared for 1.7's... i guess it's all in the Valve cover lol
my friend runs an e-cam with with 1.7 rockers and has no piston to valve problems. However the 1.7's he used didnt work with the factory valve covers and when he bought tall covers they wouldnt fit under his GT-40 int. So he sold the intake and got an edlebrock perfomer. He siad that if he had to do it over again he would have just used the 1.6's with a bigger cam.
Specs as listed on http://www.johnbleakleyford.com/partssearch.asp?search=SPECIALS
Rocker ratio: 1.60, Intake events (0.50') open 5 degrees BTC, closed 39 degrees ABC, Exhaust events (0.50') open 49 degrees BBC, closed 5 degrees ATC, duration intake 284 or 224 degrees, exhaust 284 or 224 degrees, Lift lobe .300 I or .300 E, valve .480 or .480 E. Lobe center intake 107 degrees, exhaust 117 degrees. Camshaft intake and exhaust valve events are measured at 0.050 tappet lift. For comparison purposes, add intake and exhaust lobe centers and divide by 2 to calculate camshaft centerline specification for Ford Racing camshafts.
Definitely not e-legal as you said! For comparason purposes, Stock 5.0L HO cam advertised specs are 266°/266° duration, 0.444"/0.444" lift.
b303 cam 1.7 rockers is only 0.510 lift 0.550 is max for the 87-91 block E303 with 1.7 0.530 lift.. this is way to find what lift you have b303 is 0.480 divide 1.6 is stock rocker times 1.7 = 0.510.same with the e303 is 0.498 divide 1.6 is stock rocker times 1.7 = 0.530 b303 cam with 1.73 .0.480 divide 1.6 is stock rocker times 1.73 = 0.519