3400 UIM runners port to 3500 LIM

[rsisbetter]

Can a 3400 plenum runners be hogged out enough to match the 3500's larger stock LIM ports?

[Superdave]

Can a 3400 plenum runners be hogged out enough to match the 3500's larger stock LIM ports?

the stock 3500 LIM is nearly the same size as the stock 3400 gaskets.. so Yes, i believe the 3400 UIM runners can be gasket matched to the 3400 gasket and used on a stock 3500 LIM...

[geldartb]

yes the 3400 plenum runners can be bored out. 3400 95 modifed did it to his upper.
you got to remove a good amount of material

[IsaacHayes]

Depends on what gasket you are matching too. If going by the 3500 metal upper gasket, then you will be taking a lot of material off, and the 3400 snakes down from large to small, so you will have to port pretty deep if you do that to ensure a smooth funnel effect.

Porting the 3500 upper is a lot easier. It's less than 1/4" thick deep of material to open up to whatever size you want. No runners in the 3500 upper. So you just basically port it to size and that's it. You can bell mouth it inside a little if you wish but you don't have to mess with a transistion or anything inside.

[rsisbetter]

k, i just wanted to make sure, since i picked up a 3500 and would like to use a 3400 plenum on top. and wanted to make srue since i was going to trade. I dont know why, i just dont like the 3500 plenum that much.

[rsisbetter]

thanks btw!

[IsaacHayes]

Not even mine? Everyone loves mine!!! hehehe

[rsisbetter]

oh, uh, its super tight!

[rsisbetter]

actually is way better than stock

[IsaacHayes]

hahah thanks

[geldartb]

shaved its the only way to go. the 00+ 3x00 plenums look 100 times better without the letters on and painted black

[G-U-NOT]

I think Im going to sand my 3500 plenum down and polish is till it looks like a mirror

[3400-95-Modified]

I did it yes... and yeah it was a lot of material removed, and I used a flapper wheel to blend it into the rest of the port. I dont think I have pics right here to post of it but it worked out for me. Matched to 3500 metal gaskets BTW.

I did it because it equaled easier install in my car, less "adapters" needed and such. Plus it looks stock when I open the hood... Minus the headers. LOL

[SappySE107]

There is not enough metal in the runners to get the proper taper though.

[3400-95-Modified]

This is probably why I should upgrade to your race ported upper and lower 3500 intakes... I'll probably make more power with them. Oh well, untill I find a core set of 3500 intakes I'll have to stick with what I have.