3500 exhuast manifolds on 3400

[Rootie524]

I'm looking into getting 3500 exhaust manifolds for my 3400 to hold me over till i get headers.

are the benefits going from the 3400 - 3500 manis noticeable? is it worth it?

i've also heard that the way the rear 3500 mani is designed, it is more beneficial to use 2 front manis. is that necessary? is the difference that great to justify 2 fronts?

let me know what you guys think. thanks

[Rootie524]

bumpski

[Superdave]

it depends on how your engine bay is set up, if you can run a front and a rear then go for it. The few people that have used them had tight bays so the 2 fronts worked out best.

the good 3500 manifolds flow a ton more than the 3x00 logs.

[Rootie524]

how would i even set that up with two fronts? because the 3500 front on a 3400 wouldnt be able to use the crossover because the front mani put the exhaust down and not the the right side to connect to the back.

i imagine custom work would be in order?

[Superdave]

just a pair of flanges, some mandrel 2" J bends from Summit and some random scrap pipe.

http://www.v6z24.com/jbodyforum/little-side-project-t108940,highlight,side+project.html

[RedBird]

yeah, the stock 3500 rear points almost directly straight back so most applications for custom fits need 2 fronts.

the setup works great, BUT if you go that way, put a flex pipe near the flanges if you can. i havent had any issues with the front pipe setup but the rear one has a nasty crack in it because it couldn't flex enough. took a year to crack but it eventually did.

also in a j-body with no A/C lines it clears the rack by <.5" but with the rack heat shield from a quad grand am everything is peachy.