Intake manifold interchangeability

[postmortem]

I have an aq225d (1984 gm 305, 4 battle carb) and I have a warped intake manifold. It does not seal well at the exhaust crossover and want to either have it resurfaced or pick up a second hand one one.

Does anyone have experience with resurfacing their manifold? My concern is if too much is take. Off the bolt pattern won't line up since it's a V shaped fitting.

Secondly, are the intake manifolds for 57-85 gm 305 and 350s interchangeable? There's a lot of different part numbers out there and I can't make sense of what is what. Thanks for any help.
Eric

 

[Scott Danforth]

yes, all SBC 1957-1985 manifolds are the same

throw your junk manifold away and buy a manifold for a 1985 and older SBC. they are like $25 all day for good used cast iron, about $180 all day for new cast iron, and about $200 all day for aluminum and $300 all day for marine aluminum

PS, to get your intake manifold to warp, you really really had to overheat the motor to the point you scuffed the pistons and warped the heads

 

[postmortem]

yes, all SBC 1957-1985 manifolds are the same

throw your junk manifold away and buy a manifold for a 1985 and older SBC. they are like $25 all day for good used cast iron, about $180 all day for new cast iron, and about $200 all day for aluminum and $300 all day for marine aluminum

PS, to get your intake manifold to warp, you really really had to overheat the motor to the point you scuffed the pistons and warped the heads

Thanks for the reply.

I bought the boat this way, but the compression is 145+ all the way around? Hopefully I can get a reman long block in the next year or so.

Do you have any idea why the exhaust cross over would leak (oil bubbles from there) aside from overheating?

 

[jimmbo]

Restricted exhaust from a stuck closed back flow preventer on one side is one possibility.
As said any pre Vortec manifold will work. Some of course will be better than others with regards to performance as well as corrosion resistance. I don't know if your engine is using a squarebore carb or a spreadbore, that will affect manifold choices. Forget about adaptors, none of them are any good, despite their use by mercrusier