Laird1978

I plan to put a 76 454 into a 78 Coupe. I am wondering about the exhaust manifolds. Does anyone make a ceramic coated header for this swap? If not what would the part numbers be for the stock 454 exhaust manifolds so I can look for them? Thanks

Durango_Boy

I think Jet Hot makes a ceramic coated header for big blocks in Corvettes.

Clue

I have Hedman Elite on mine 1974 BB, they sound really good.

rpoL98

you might end up buying the exhaust manifolds (stock GM, sanderson, etc), deciding whether to Extrude-Hone, and then sending them to be coated to Jet-Hot or whoever your preference is.

sounds like you're leaning towards cast-iron manifolds. I put a 540BB into my 78SA, but I used Hedman headers.

Doug73

I have an 81 with a 454 installed. Hooker makes their headers with a heavy flange that keeps the gaskets from leaking. Problem is #1 & #3 tubes are too close to the spark plug boots. I got some 1 3/4" mandrel bends and had the tubes rerouted. After a recoat all is well. You can't see any of the welding as the engine is a tight fit. Headman's and others don't have as heavy flanges and have been known to cause problems.

If you are installing a better cam they frequently require headers and a higher stall converter if your running an automatic. If you do 4l60-Es won't take it. Trust, I had three trash themselves in 500 miles.
A TH400 is bulletproof and a 4l80-E is a close second. I'm chasing the parts now.

kramer9

I am doing a buildup of a 78 (http://rockymtninfo.org/ABetterVet.html)

I was orginally planning a 383 (405 hp), I go approaced about a 454 for $3000.

What considerations/mods did you take into play when putting a 454 in?

gavanm01

If you have a/c you may wish to consider a "close-fit" design. Hooker makes them. On my '69 I had a devil of a time fitting the standard without some whacking and hacking. Check out the JetHot Sterling coat; mine still look great after three years and 35,000 on my 454 stroker.

markdtn

Paragon sells some repro manifolds that aren't as pricey as originals.

tlynam

The original big block large "header" style manifolds have interior diameters similar to aftermarket headers, but for the fact that they are 2 1/2 inches at the ends. No real difference in performance and without the headaches of headers.

enkeivette

Primary tube length plays a factor.

rpoL98

just wondering, the versions of cast iron exhaust manifolds being sold nowadays, presumably reproductions, do they have the same generous interior dimensions?