3100 to 3500 upper swap

[El_Diablo]

ive been thinking about this swap for a while now and ive been wondering what parts i need... ive heard that i need a 4.3 throttle body but what does that come off of? and what about the adapter plate? can i keep my cruise control? oh and what about the "clearancing" around the neck? i know its a problem with the FPR not clearing but how much material would i need to remove and how thick is the neck? i would be interested in a P&P job after this so thats a concern i have... i know the coils dont fit in the stock location but other than that what do i need to know?

oh btw i have a 98 chevy malibu with the 3100sfi



TIA

[asylummotorsports]

To begin with the 3500 UIM will only work on 2000+ 3100's.

[El_Diablo]

okay well you say that but you dont give me a reason why? wtf? and aren't the lowers are the same except for port size? again, WTF?

so your basically saying that for some misterious reason i have to change to a 00+ 3100 lower...... ooooooooooook, now how bout a lil info

[bszopi]

Couple reasons really... Port size and alignment for one. There is a chance that the 3500 port is actually bigger than the old 3100 port AND surrounding metal. Next would be bolt hole location. The 3500 plenum only has 6 bolts (vs 12 for the old 3100) and they are in different locations.

As far as other issues, I'm sure I could dig up a couple more, but those 2 above should be reason enough.

[El_Diablo]

damn

that adds a bit more to the price now doesn't it






so now i need a 00+ 3100 (or any year 3400???) lower AND a 3500 upper.... sux

[WhiteRaider]

A 3x00 LIM won't add much cost to the equation. You can get them for 30-35 bucks on car-part.com .

[MidnightriderZ24]

add gaskets, oil, anti freeze etc.... btw im the 1 making the plates. ill only be making them for another 3 months then im giving the design to sappy

[El_Diablo]

yeah you can get up to 200 pretty fast with the LIM and gaskets


i'll prolly just end up making my own manifold eventually..... these engines need more air