speedkills previously posted:
"I'll be curious to hear how the ceramic coating does at keeping underhood temps down for you. I'm thinking I should have coated or wrapped my headers, the heat just pours off of them."
My only previous similar experience is with the v6 in the cj5....When I got it, it had fenderwell headers and I ran it that way for over a year. I then found some used OEM manifolds and painted them with VHT paint, and redid the entire exhaust (no more effing side dump cherry bombs!). The headers I took off were rusty (replacement was needed as they rusted through and cracked at the mounting flange) - not sure if they were ever coated or left natural and just oxidized. But switching to manifolds made things cooler under hood...although it wasn't a huge issue. I had these manifolds ceramic coated more out of ease (take them to a shop) than trying to properly cure the vht paint in the oven etc. The VHT paint has never had an issue on my cj - but guessing the little v6 doesn't put off quite as much heat as the v8. I thought about trying to wrap or paint or ceramic coat the headers - I like the fit of the headers on the v8 - but everyone I know who has tried to vht paint the headers, it lasted for awhile (a few years), but eventually it has issues. I think headers just get so damn hot compared to iron manifolds. I think a good wrap could really help with heat - but it shortens the life of the headers even more as it also traps moisture and increases corrosion. The cost of coating headers was more than manifolds, and even when coated, they only last 10 years or so of lots of use, and getting the flange to seal against the head is always a PITA on headers. Plus, even with ceramic coating, the headers will discolor due to heat - although its only aesthetic.
So, in other words, I went with old school manifolds, they'll never need replaced, they will always look good, they might help with low end torque compared to headers (like v8 350 isn't going to be enough as is!), and I expect they will help with underhood heat more than anything else. But, if you are stuck with headers, then think about getting them ceramic coated....I think it'll help with heat, but maybe not as much as iron manifolds, but it will help with longevity and appearance. I used these guys - obviously no comment on long term durability, but in terms of dealing with staff and what I judge of the initial quality of the coating - highly recommend!
https://www.appliedplastic.com/