Here is the Alpha vs Cl for the 35B vs the 35B MOD Piper vs the Riblett 613.5
Has me thinking which way I should go moving forward???
After a proper run up, ie: mags check prop cycling, carb heat check or what have you, I always pull the power to idle and then do the P lead check as stated above. if the engine doesn't quit than you have a hot mag. if you do the check at a higher power setting you have a higher likelyhood of exhaust system damage...do the P lead check at idle or just before shutdown.