l`m stumped here.460 with t/chain just done,new heads and just replaced carb with factory recon motorcraft.Timing set.The engine runs okay,seems to be loading up on full throttle and the real problem happens when l put the air filter on-the engine bogs bad and won`t take throttle.l`m thinking the power valve is opening and flooding the engine due to the vacuum caused by the air cleaner restriction.There is no interference to linkages or carb assy. caused by the air cleaner,l checked this first very carefully...Any ideas anyone?

 

If you cant smell gas , then chances are its not loading up. Try advancing the timing by ear till it runs . I have an 83 460 that will not run on factory timing specs. I have a 650 edelbrock and after I advanced the timing it ran fine.Also the new chain could be a tooth out and that may be part of the problem too. Good luck Mush

 

How about replacing the power valve to eliminate that possibility?

 

thanks amigos.Well,l did advance the timing beyond factory spec. because at 7000 feet you really have to if you want any power at all but l`m at 38 degrees advance at 3000 rpm,and about 18 degrees advance at idle.ln the past l`ve set timing with a vacuum guage but this method produces 30 degrees advance at idle...seems a bit excessive even at 7000 ft.l`ll check into buying a better spec power valve for this altitude and keep you posted.thanks for the replies,much appreciated