would it be possible to use regular NA 2.8/3.1 exhaust manifolds in a turbo application if you used the rear (firewall side) manifold outlet as a place to mount an external wastegate?  or for that matter could you use regular 3100/3400 exhaust manifolds when doing a 3x00 topend swap?  could this be useful in a custom turbo/downpipe project?
joshua

use 2 front exhaust manifolds from the 3100/3400 like we did on out 3.4L DOHC's and it will work. the front manifolds are a log style that will give equil flow off each set of cylinder banks. you want to hook the external gate at the collection point or you will cause one set of exhaust banks to run leaner then the other.

then make a custom crossover to the turbo. i don't think the TGP X-over will match up to the new manifolds.

if you get the parts and want all of this done professionally, you can drop the car off with me and i will get it all done properly.

Quote from: RedZMonteyou want to hook the external gate at the collection point or you will cause one set of exhaust banks to run leaner then the other.

that's what i was afraid of.  

i know you can use the front manifold on the rear of a 3.4 DOHC motor since the exhaust ports are spaced evenly, but i thought the 3x00 manifolds had unequal spacing like the 3.1?  wouldn't the center port be WAY off if you tried using a front manifold on the rear head?

call a dealer and see what the part numbers for the exhaust gaskets head to manifold. if they are the same part number they should work.

unless i am retarded and missed something i thought you could on the 3x00's as well. they should be semetrical. do you have the heads? if the stock rear one off the 3x00 is like the dohc you won't be able to plumb a downpipe around it.

Shane