I was gifted a 302 with GT40P heads in a complete, lo mileage 2000 explorer.


Im currently running a 351M, lots of torque, but really hard on gas. Like single digit fuel economy bad.


Ive owned 289s and 302s before, good power, great MPG for a V8, but not much in the torque department.


This is going in a 78 F-250 supercab 4x4 with 4 speed and 31 gears. Needs to pull ungodly overloaded trailers up mountains, plow snow and occasionally 4 wheeling.


I was thinking a dual plane intake, 600 eddy carb, and a mild RV cam might really put some torque into this 302. I don't plan on using the EFI on it.


Good or bad idea on the 302? aDVICE? BUILD RECIPES?


THANKS

 

The 302 sounds like a nice engine for the right vehicle. I don't think it would be happy in a full size 4x4 PU with towing duties though. In that application it would be working so hard I doubt you would see much mileage benefit. There is also lots of conversion cost as the transmission pattern is different + mounts and some wiring.

I'd suggest pull and sell the engine for a car or lighter PU application and use the proceeds to build a nice higher compression 400 out of your 351. That would give much better performance and maybe better mileage if you go easy on it.

 

A 302 would be my last engine choice in a 4wd 3/4 ton truck that is used for work and towing. You can't expect a small engine such as rhe 302 or even your 351m to do what you want it to do and get good fuel mileage. 460 or diesel is what you need

 

You will not be happy with a 302 pulling. An underpowered motor will suck just as much gas as one with adequate torque when pulling heavy . Build the 351m into a mild 400 and enjoy even more bottom end. Gas motors suck a lot of fuel when towing; thems the breaks. I've been able to 14 mpg on the highway with my old 400, haven't had the little 2wd on the highway enough.

Single digits in town and while towing but I'll let u know after switching to EFI if that changes

 

There are lot of things you can do to increase the torque output of a 302 but the specific motor you have already has most of them done. The EFI intake is well suited to low end power and the heads flow well for that too. You will probably lose torque going to a carb and dual plane intake. Headers will build a bit of torque and a RV cam might make more torque but it will probably move peak torque up in RPM over the stock cam.


A 302 is a good motor but I do not believe it is well suited for the application you described. With the added cost of changing your transmission or at least your bell housing, motor mounts and other parts I believe you would be much happier with taking that $ and putting it towards the motor you currently have. A well thought out build on a 351 (or converting to a 400) should make much more torque than the 302 and with the right parts get very similar gas mileage. You would probably see a bit lower mileage unloaded but a bit better mileage when loaded or towing.


Are you getting single digit mileage loaded and towing or just driving around?

 

Might sound crazy but my stock FE 390 got about the same mpg pulling a 10,000 lb trailer as a 3.5 ecoboost towing the same weight...that's coming from every 3.5 ecoboost owner I've spoken with and all the reading I've done about the 3.5 ecoboost. Running empty the 3.5 wins the mpg contest hands down, but working engines hard still sucks gas no matter how small of an engine you have.

 

[QUOTE=hail destroyer;16287905]I have been building my own motors for DECADES, both diesel and gas sonny boy. I even turned an oldsmobile diesel motor into a gas stroker that ran bottom tens, no turbo, no N20, no EFI. Hows that, wise guy?







I find it funny that you're asking this question, after making this^^^and other posts in another thread.