70torino429

well this engine isnt going to go into a mustang but its going into a car similar enough, a 1990 crown victoria with the 5.0 w/aod trans. since no one on the crown vic boards is really daring enough to build one of these for a crown vic i wanted to ask you guys some questions since i know theres quite a few 331 stangs out there. i know the mpgs would be a little worse in a heavier car but im just looking for a ballpark estimate and was curious what kind of mpgs you guys are getting with the efi 331 strokers? im just going to do a mild build probably with some ported e7 heads or maybe some gt40s, since its a daily driver that id like to get some good mpgs from. if you were building this is the standard route to go with mass air and get a custom chip burned? as well as a calibrated mass air meter for bigger injectors (are bigger injectors needed?), since im a little confused on the electronics part of it so if anyone has any advice or pointers there it would be greatly appreciated. also any other suggestions for camshafts, and such for an engine like this, keep in mind i want to get good mpgs and hopefully get around 300hp/350tq or more out of it but if i have to sacrifice some power to get decent mpgs ill do so. thanks in advance for any help

luckythirteen13

you can get decent milage out of a 331 if tuned right and the right parts are used. a lot of it is how you drive it. i would look at better heads then gt40's for a 331. they will work but will choke you down in the upper rpms. id go with a set of 24# injectors maybe 30s with decent heads

mjr46

if 300 is your goal a well built 302 is all you need, e7's or gt-40's will hamper the hp you could be making......I'D GO 347 but that's me

70torino429

id like to get over 20mpgs if possible but im really clueless as to if it is possible, thats why im staying away from the 347/351 and also ive heard longevity and reliability is slightly better with a 331. im trying to figure out if i can get decent mpgs out of a mild 331?

primetime5.0

here we go again

70torino429

primetime5.0

the 331 vs 347 debate

70torino429

i just have my mind set on a 331, wasnt trying to start anything. if i wanted to go bigger than that on cubes id just swap a 351 in but i want to retain some decent mpgs. i was hopeing maybe someone on here knew what kind of mpgs their 331s are getting?

redpony88

i never got to figuring that one out. i had one in my old fox and i'll be building another 331, personally i feel as you do, if i want more cubes i'll go 351. but i got decent mileage out of it really. they arent bad on gas. which is why i'm gonna op for yet another one in my daily driver

70torino429

whats your opinions on some iron heads like the windsor jr, windsor sr or the dart iron eagle heads for an engine like this? are those heads any better than gt40s? the place where im really confused is the electronics aspect of it so if anyone has pointers on what will be needed there itd help alot