Engine / Build Options and Opinions

[EB70]

I have a 70 EB. Solid but older 302 in it, 3-speed with 37" tires and 4.56's. When I built the axles our speed limit was 55. I'd probably hit the 65 MPH area twice a year. It is OK at 55, not very good at 65. I seem to be the only guy on here that doesn't care for too-low of geared rigs. I should note that our road is now 65 and it is 20 miles each time I drive anywhere one way.

How I use the EB:

For moderate use, maybe 100 miles a week, and then longer trips 2-3 times a year here is what I am thinking about. I should note I do sand maybe once a year and a lot of deep snow 4x4ing.

What I want from it:

Smooth engine, quiet, as good of MPG as can be expected for what it is. Not interested in switching tires, maybe run some 35" ATs in the summer at some point.

What I have to use:

300-6 I'd like to try, an AX-15 swap as well. I do have a basically new crate 302 roller out of a lincoln. Some EFI parts for that. My guess is that either the 300 or the 302 will end up with the FITech system. I doubt I will use the OEM system for EFI.

Assuming that you had a good running 300, the mechanical abilities to install it and the shop etc.

What do you think I will see from a 300-5-speed, 37's and 4.56's?

Convince me why I should run the 5.0 over the 300? I am not a racer, I want quiet, torquey and as efficient as I can.

I'd look at other engine options as well.

Thank you as always.

 

[englewoodcowboy]

It all depends on what you want to do and how long you are willing to do it. The easier faster swap would be the roller crate motor you have, direct drop in and the NV3550 is pretty much a straight forward swap as well. I would look at some cam options out there to get a broader low end torque. With the tires and existing gearing you will be pushing it to try and use OD off the top of my head, you may be looking for some deeper gears or drop in tire size to make up for it. I think with 4:56 and 35's it would be ok. As for wanting the 300-6, while they are good and full of low end torque, they are tight to fit in the bronco without major modification and fabrication. It can be done but is rare to see for the reasons stated. Bottom line I think the 302 roller will be the more affordable and much faster turn around but again, it all depends on you, how much you have to work with and how fast you want to have it back on the road.

 

[Justafordguy]

X2, In my opinion the 302 roller with EFI is a much easier/better swap. I also think a 5 speed, 35" tires, and 4.56s would be a good combo.

 

[Rustytruck]

I'd sell off the parts and go with a more modern stock fuel injected 351. More torque down low to pull the tires and enough HP up top to pull the top speed without the motor working too hard.

 

[needabronco]

The 300 will require you to modify the firewall and likely the core support. It has been done a few times, and I know it's a lot of work. 300's aren't exactly a high RPM engine so your not really gaining anything for the highway. Off road or in the snow it'd be a blast!

What you really need is an overdrive transmission for the highway and then you'll likely need more torque to push that barn door on 37"s down said highway.

I'd opt for an injected 5.8 and your choice of a 5 speed or an overdrive automatic. An injected 5.0/302 could also do the job but why not just add 50 cubic inches to the equation?

 

[Broncobowsher]

300 + 5-speed + 37s = driveshaft angle issues.

 

[EB70]

I think you're right on the 302. I have four EB's. Really would like to do a restomod thing, but I got to looking and the one that I drive is better suited to "kind" 4x4ing and I will redo the other one later. Mine is in a sweet spot. Big, but not too big. Not rusty at all, pretty straight, but just enough use and mods to where you don't mind it if something did go awry.

I need to use the roller 302 in something, and I want quiet, smooth and efficient. I already have stainless steel headers on the 302 with a good exhaust etc. No drivelines to mod and so forth. I'd probably be happy with it. I currently have a stock 69-70 302 with no mods other than the headers etc. It is fine other than showing some age and some leaks etc. Runs good.

Save the 300-6 for the crawler build it looks like.

I would imagine a good running roller 302, with a 5-speed and so forth and I should be good for what I want. I think the engine would last for a long time, particularly with EFI. I may use the factory EFI not sure.

The engine was a low-zero mile takeout or demo engine etc. from a tech school. I think it has been ran, but barely. I have all the EFI stuff or most of it, it is the lincoln style from 88-89 ish.

Thanks, I needed some support and guidance. I have been putting engines where they don't belong etc. for 30+ years so the 300 is doable. I was going to do the intake etc. so I didn't need to cut anything.

The last issue, which is minor, is the way the Bronco would be built would increase its value. I think a 300 isn't helping me there. A roller 5.0 with a 5-speed would help.

 

[sykanr0ng]

Either a 5.0L or a 5.8L and a 5 speed overdrive transmission.

Save the 300 for a tube frame crawler where there is no space constraints and no loss of value putting it in.

 

[EB70]

Kinda my thoughts. I really don't mind the stocker 302 at all. It isn't that I don't like HP, I just have other rigs for those purposes.

I do like 300's and the tractor qualities. Not sure I need to put one in my most valuable -so to speak- truck.