Worth Swaping 3400 heads onto 3100 block???

[GPTuner]

First of all, whats up guys, This is my first post on here so you can all just call me NEW-B for a while haha

My main question is....well is there a difference in flow chart numbers between the 3400 and the 3100??? since the difference between the two motors 5 HP im wondering if it's even worth the trouble. Would I see any gains?? Or will it not do much of anything.


Also i plau to swap the 3400 TB and upper intake onto the 3100, since i will have those off i was wondering if i would see anything more with the 3400 heads????

Thanks in advance guys

[Manitcor]

the difference is actually more like 20hp for the 99 and earlier 3100s and less for the 00 and better.

For the work involved I would just swap the entire engine since a low mile 3400 can be had pretty cheaply.

[SappySE107]

what year are we talking about? There is quite a difference in casting quality between years. The non roller castings are pretty bad. I haven't flowed the head yet but as soon as I am doing trying to flowmatch this last exhaust port I will throw the 95 3100 head on the bench and see how it looks. Aside from a single cylinder, I am guessing from the looks of it that the flow will be pretty difference between ports.

[GPTuner]

Its a 2000, 3100 and these parts are from a seized 3400 same year motor.

I know they will bolt right up, ive fitted a new headgasket for the 3100 onto this 3400 and all the holes line up perfectly. but i havent pulled my heads off just yet, to do a comparison, and take measurements on the intake, valves, and exaust ports

[Manitcor]

wont matter for you then, IIRC the topend on an 00+ 3100 and an 00+ 3400 are identical.

[GPTuner]

Damn I was kinda hoping they would be somewhat larger....oh well, i guess i'll just gasket match everything insted, thanks guys

[SappySE107]

Yup, identical. If you pull the heads, check the casting number on them for me.

[GPTuner]

no problem

[Syn]

got the 3400 intakes?

[GPTuner]

I have the whole 3400 motor, the botom end seized, so im trying to make good use of the whole top end lower and upper intake manifold, heads, TB, anything i can swap over, that will make a difference

I havent gotten around to any of this yet, im waiting for the weather to be a bit less crappy so the motor sits in a garage full of crap till i can get around to it, while i work on my GTP