MPG after head build?

[88BlackS-ETA]

Im going to build my m20 head within a year and was wondering what type of mile per gallon I should expect. Currently I get 21city and 26hgwy.

I should have it done within a few months to a year. I have almost everything (don't have coil pack, intake, and cam gear yet) and just waiting on money to do head work and for tuning.

Here is about the car and whats getting done.

1988 325 SuperEta
Autotrajic trans
2.93 LSD

Head build:
885 head
Port and polished
272 cam
IE HD rockers
New valve springs
Head milled
3 angle valve job
New valve guids
New valve seals and all gaskets
Head cleaned

ECU and intake/exhaust and ignition
I will be running MS PNP
The MAP will be T'd in to the FPR vacuum line
The intake will be a straight pipe with a IAT sensor in it
The exhaust is ebay long tube headers into a Y-pipe 2.5" high flow cat back to a vibrant 2.5" inlet and dual outlet
Car will be tuned by a local shop that specializes in MegaSquirt
Coilpack controlled by the MSPNP (distributor delete)
Adjustable cam gear


I don't plan on racing anyone just doing this so the car can get out of its own way while getting on the highway and piss off the occasional ricer that has a loud exhaust for no reason. I drive mainly back roads and little on the highways. And when I do drive highway its usually the turnpike so not to much traffic so its get up to speed and cruise.

[nando]

if tuned properly I wouldn't expect it to change much, but getting there will take some effort on your part.

[AlphaE]

really?? my supereta in stock form got closer to 26 around town and like 29 on freeway w the 2.93 diff. After doin the i swap i get about the same if not better. Best i got was 33mpg on freeway. back tires are a bit undersized but not much..i got green top injectors and CAI from kamotors. otherwise its stock everything (cam ecu exhaust etc).

i did swap in a 5spd so maybe thats makin the difference??

so, you should get the same"ish" mileage would be my guess..