I've heard aircare is on the way out, so you probably don't have to worry about it up there
These are replacing the same part# so fit is the same for me
No mods at all
Just put 'em on and break in the gaskets
There's lots of clearance to get at the bolts with a stubby wrench and a socket here and there, and even though they claim they don't fit angle-plug heads, they work fine on mine
My '78 truck is a heavy half and in 77-78 they eliminated emissions controls on these models for HP issues, so I have
piles of room to pass and do so within recommended limits, even with a 355HP crate motor and a 795CFM Q-Jet
The flanges are 5/16" and the ports are raised
I've never had a leak ever from the first set, until they rotted away
When I install new gaskets on these, I torque down by feel, run the engine to temp and torque again, then go for a hard run, torque again, then torque a last time the next day after they have fully cooled off
After doing this, I've never had a header gasket leak, and I've replaced the gaskets twice on the first set of headers
I use Felpro 1406
I only wish I could have afforded ceramic this time around
These headers are $199 state-side, and $218 here
The ceramics are about $385 state-side, and about $525-50 here
Some pics of the new headers, and where they're going
