Okay, I'm installing a Magnum engine in my 67 Barracuda. Due to budget constraints, I'll be using my old 273 exhaust manifolds. What gaskets should I use? It probably doesn't matter, but Fel-Pro lists at least 3 different sets.
MS9939 Application: 1967 273
MS90460 App: 1969 340, 1973 360
MS95480 App: 1993 318 and 360 (magnum)

I'm assuming the magnum and 360 gaskets have larger ports, but should still seal my manifolds.
Anyone have any wisdom to share here? Thanks!

I needed the 273 gaskets with my 273 ex manifolds on an 80's 318 so I'm ASSuMEing you'll need the MS9939

I have an 87 318 I put into my 65 Cuda, the overlap between the 87 exhaust port and the 65 273 manifolds is very small and if not carefully attended to you will have a leak.

Test fit the manifold to the heads and see how well they fit up, outside the car if possible. I ended up using the 273 steel shim exhaust gaskets as I felt they would be less likely to blow out.

Thanks guys for the tips. I ordered the gaskets for the 273. When we do a proper exhaust for this car, I'll upgrade to either better manifolds or headers.

iirc magnum ex manifolds will fit the early A SB but I dont remember if that was a drop in or if mods were needed & the early (92-early 93?) mag manifolds were way larger with either a 2&1/8 or a 2&1/4 outlet & the later ones were ~1&7/8 which might be what the 273 logs are.