Big block heades, which fit???

[JeffHK5]

First i'll tell you what I got :
77 K5 454 in stock location
400th,ORD gen2 1410 H.A.D front shaft and D60
very flexy 13 leaf Alcan 56" front springs 8" lift
In the last month I have tried both Hedman and Flow Tech full length headers with bad results. The Hedmans hung down very low and looked as though they could hit the diff/dshaft under full stuff. Both the Flow Tech's (Holley) and the Hedmans put the collector at a strange ang. back toward the eng. block/trans mounting surface. I have not tried shorties or tight tuck type street rod headers but thats my last option other than stock manifolds. My buddy has a BB Sub. with Hooker Supercomps $$$ that don't fit all that great and required to be beat and bent to fit, $400 bucks is alot of cash to do a hack job on. And the worst thing is it don't take a lot of kinks and dents to kill the hp gains of a header.

So who runs what ? and with what results?

My 454 has rv cam alu intake and Holley EFI and could use the flow of a good working exhaust and stock BBC manifolds are not known for there performance.

Thanks Much
Jeff

 

[Z3PR]

From what I've understand, the Doug Thorley Tri-Y headers fit very well, and are one of the best headers you can get for a 4wd GM truck.

 

[k20]

I must agree, ran thorleys on my 350, bought em again for my 496.