hi I have a 94 f150 4x4. eventually I would like to swap in/rebuild the 302 I have now. at the same time as the motor swap, I want to swap in a zf5 and go to 4.10 gears... I have 3.55 now. the options i'm considering are rebuilding my 302 to a 306 or a 331, buying a 351w and rebuilding as still a 351, or going to a 408. I know that's a wide range but im just looking at all options right now. im looking torque low in the rpm range. i don't like revving an engine too high and will never use it for racing or messing around. i know there are a lot of variables that determine the torque rating. what would be the best fit motor for my application. i don't tow much now but could in the future. also would like to improve my mileage, or atleast maintain as it'll be my DD.

thanks, ben

 

also i guess im a bit biased towards my 302 as like any guy on here, ive got a connection with the truck and motor. i know the 302 is known for higher revving but is there any setup that will give me some low end torque?

 

Boost would be my suggestion. And a larger big block with a heavy crank. That's where torque comes from and most boost applications can score 18mpg

 

I would REALLY like to avoid boost. I don't need the engine to pull a house of its foundation, I just want to know ill be able to tow when I need too. and going to a big block complicates it more than id like with motor mounts not being compatible and such. Id really like to stay with the 351w and 302. Im not looking for whats the best set up altogether, just the best between a 306, 331, 351, and 408 when it comes to towing and mpg combo.

 

A 351W with 9:1 compression, a decent RV cam, dual exhaust with headers, and a little computer tweaking to make it all work, combined with the ZF tranny and 3.55:1 or 3.73:1 gears will pull anything your F150 would ever be comfortable with, not kill your wallet to build, and as long as you don't get on it a lot probably return around 15-17 mpg empty. It will be cheaper than building a 302 to make similar power, and it will last longer than said 302, which will have to work harder with less. Just my $.02...

 

Anybody that tells me they have a 351W that gets this kind of mileage in a truck, I call BS on.

The most torque for the least amount of money would be to swap in a 460. Ask me how I know.

 

I've seen carbed 351W's get 15 in a 150, an EFI 351 should have no problem, even slightly built.
I agree, 460 makes way more torque (look at my sig) but he specifically said he didn't want to swap in a big block. And although they have great power, they get lousy mileage. I get about 8 town/11 highway... stupid duallies...

 

how do you guys think this setup would be... edelbrock performer rpm intake manifold, bbk throttle body, edelbrock performer rpm heads...bare, scat rotating assembly kit for a 306, and xtreme energy xe266hr cam and full kit from comp cams. edelbrock recommended me the heads, and based on the heads, comp cams recommended me the cam.

 

I understand this isn't the best setup for exclusively low end torque but how would it do power wise for a 306?

 

351 would be my choice but it would need to build it proper to be the best all around. I heard they tow like junk. Get your gearing right and the power band put in the right spot you can probably do some swell gas mileage.

 

Maybe one time on one tank, not day-in and day-out, IMO. BTW I have 3.55 gears and my 460 does about 12-12.5MPG all around, but I don't have a dually, either.

 

I have a 3.55 geared 351w and it averages about 13 city driving and around 15-16 highway driving. If you're doing mostly highway then I could see 15. If not then unless you drive like grandma (not I haha ) then it may be a little less.

 

I have seen over 17mpg at a steady 70mph cruise on level ground from my 5.8/AOD/3.55 combo.

 

I get frustrated with a few things when I see stuff like this... Sorry for ranting in your topic, but it will have relevant info throughout.
First, you're willing to properly rebuild a 302, but not the 351... Meaning, there's nothing special about your "306". It's a 302, period. Nothing's been done other than bore it, and mathematically it's a 306 CID. But yet you say you'll keep the 351... As a 351.... Meaning you're not going to bore it before you rebuild it, because you'd have listed it as 358 or some irrelevant number like the 302 if you had...
So, whichever engine you decide, it should get bored the minimum required to remove all the wear and clearance for the type of pistons you purchase.
Second, if you get the crank resized and rods done, you may as well have bought the 331/347 stroker kit. They have fixed the oil issues of the 347 by lowering the wrist pin. It's a little different rod/stroke ratio, but it's still pretty good. If you do a 302 block, I highly suggest a stroker.
Third, the cost of parts and rebuilding the 351 vs the 302 is nearly identical. Maybe a few hundred more for the 351. So don't let the cost deter you from doing either engine. A stroked 302 may be cheaper just because the 302 truck intake is plenty nice for your application, where as a 351 should have a better intake. (If you send me an efi 351 intake I'll port the lower to a 302 upper for you, it's better than nothing and it's way better than stock)
Fourth, stick to a budget. figure out your max investment, price out parts, ask us our opinions BEFORE you buy. Camshaft selection is very critical unless you want to go get a custom tune. Ask questions, we don't mind answering.
Last, search, read, search, read, SEARCH AND READ.... Ask questions, read.

 

It's the complete opposite of what you asked for originally.. all topend horsepower and no low rpm torque.
If you really want a torquey truck motor options start with a 351.. you need to completely forget about a three-oh-anything.. just not enough displacement.