would a piston designed for running tfs twisted wedge heads be compatible with tfs highports? valves are 2.1 and 1.6. if so or if not, what are the advantages and/or disadvantages of running these on a set of highports?
That's going to depend largely on the cam's lift and timing. If PtV clearance is too tight, pistons made specifically for TW heads with 2.02" valves will still need to have valve reliefs cut. The reliefs that they currently have will most likely be too small for a 2.100" valve. If memory serves, valve reliefs are cut either .030" total or .030" per side larger than the intended valve. This means that if they're designed for a 2.02" valve they're, at most, 2.080" in diameter. Running them as is with the heads you're asking about runs the risk of the pistons hitting the valves.
when i say the tfs tw piston, i’m referring to the DSS GSX pistons, flat top, 3cc valve reliefs, designed for a TW head. sorry for the error in description, but either way, if i can loosen up the ptv clearance (2.100 valve becoming a 2.160 relief and 1.6 becoming 1.660?) would i be okay to run these after trimming the valve relief pockets down? as long as they valve reliefs are large enough for adequate PTV clearance?