what is the difference? port shape? just curious if theres problem with using them on even standard SBC head not a D-113 head.

 

Ttt

 

Most, if not all, will. A lot of people are using L98 headers on their LT engines. Most headers for "D" port heads don't have "D" port tubes. Have you found a good set of long tube LT headers? It seems long tubes are a rarity for the LT engines. That is why many LT owners have gone to L98 headers.

RACE ON!!!

 

I didn't find any LT headers but my idea to try and look smog legal here in california is a good one(IMHO). Hooker makes a shorty 1 3/4" which looks like an identical stocker manifold minus the air injection lines. I can work those in to make it look stock and i can use the stock heat shields to cover em' up.

I just noticed that on my buddies 97' LT1 Trans-Am the the outer bolt holds are futher spaced apart than the L98/L83 cars are. other than that his stock exhaust fit fine on a junk SBC heads i got in the shed. this leads me to believe they can work on an ealier head if i can drill a new hole in the flange to bolt it up perfect. looks like it might work. The D port exhaust on the LT1 looks bigger than the standard exhaust port on the SBC head which should work fine. If its the other way around i could see running into some problems with flow.

 

They will bolt up. The biggest reason long tubes aren't legal on later cars, is that they displace the cats in the head pipes. Your '84 never had cats in the head pipes. You don't have to move any cats to use the good long tube headers. I think shorties are a waste of money, and the 1 3/4" tubes will only aggravate the problem on your L83. Has anyone applied for and received an E.O. for the '84? There is no reason they couldn't pass if a manufacturer wanted to go to the time and expense. Maybe it wasn't cost effective to only certify the 1984s and '85"s.

RACE ON!!!

 

Shin - My headers from Exotic Muscle are for a LT1. The big difference is the air tubes. The LT1 headers have a single air tub in the third cylinder on each side. Other than that the fit is good and they bolt right up without modification. You could also run a L98 header with air tubes....