340 duster only good for a couple of burnouts.....

well youve got my attention. heres what ive got,original 72 340 block, just installed 302 heads that ran fine on my 318, new lunati voodoo cam and lifters 454/475 lift. stock pushrods and rockers, ld4b and 750 QF slayer, engine pulls to 5000 then starts crappin out, runs very nice below that. its wifes car so i dont beat on it ''too'' hard