Does anyone know of companies who make a 1 3/4 headers for a 71 mav. with a 302. second, will a x-303 cam work with stock flat-top pistons with out fly-cutting
The X-303 is smaller than what I am putting in mine, and I haven't encountered any problems yet with mine at .560 lift. Mine are flat top with valve reliefs.
The general rule of thumb is Any time you exceed .500 lift it is a good idea to check the piston to valve clearance. I have an X-303 in my 308 with no problems even my thin (.025 thick) Cometic head gaskets but my pistons are Speed -Pros which have LARGE valve reliefs. On the other hand I`m in the middle of a heads,intake and cam swap on my sons 5.0 Mustang and we are using a cam with .498/.518 lift ...the heads are 1972 302 that have been milled once and trued up a time or two over the years and have had 1.94/1.60 valves installed. With a .042 (Fel-pro) gasket I only have .001 clearance on the intakes! You need a minimum of .080 int. and .100 exh. SO this weekend I will be fly-cutting the pistons. P.S. Frank told me he thought it would be ok to run it "as-is" because it would probably 'clearance" itself!
I bought a set of Hedman Hedders from a member here and they are designed just for our cars. Longtube and mean looking. I'll be installing them after the engine is re-gasketed since it is wet.
Question? why do you want 1-3/4" headers? Their too big for a 302 unless your making 500hp and winding 7000 rpm where there is a need for that kind of flow. We only use that size on a 500+hp 351 cu/in alky burning 8000 rpm dirt sprint car running 1/2 mile tracks.
