Anyone install a 300 straight Ford engine w/auto & transfer in 66-77 bronco.

[SLC]

Wondering if anyone has installed a 300 straight 6 Ford engine and auto trans w/ transfer in 66-77 bronco…mine is a 71 frame.

 

[Timmy390]

The 300 has been done a few times. There was a really good writeup on another forum that's no longer around.

As I recall the firewall need modifications.......

Some who's done it will chime in.....

Tim

 

[SLC]

Wondering if anyone has installed a 300 straight 6 Ford engine and auto trans w/ transfer in 66-77 bronco…mine is a 71 frame.

Thanks I’m glad I didn’t buy engine yet.

 

[Timmy390]

Times like this I miss "Broncofix"

Here is more info
https://classicbroncos.com/forums/threads/4-9l-300ci-6-cyl-in-a-bronco.241448/
https://classicbroncos.com/forums/threads/would-an-efi-300-fit-a-bronco.232443/

Tim

 

[66broncoCT]

I did the 300 with factory ford EFI (huge intake!) from a 1993 F150. I opted to push the radiator forward right up against the back of the grill that way minimal firewall mods were needed. I did still have to trim one small section because of the efi intake, I think if you went with a carburetor it wouldn’t be an issue. I keep the 3 on the tree though so no help with transmission. The 300 had the regular small block ford bell housing though so any of the regular transmission swaps should work. Just need to get the right flex plate as the 300 need a neutral balance not weighted like most V8 engines

 

[Timmy390]

I always thought the 300EFI M5ODR2 swap would be a sweet combo.

Tim

 

[Broncobowsher]

You will be fighting length. The original 170-200 I6 option is a fairly tight fit. The bellhousing is shoved back further than the V8 version. That makes the I6 3-speed a shorter package than the V8 transmission package.
The 300 is the big block version of the I6. It is longer. The automatic transmission options are all based on the V8 transmission length. So you are looking at putting the longest engine around, with the longest transmission, hang a transfer case off the back, and put it in one of the shortest engine compartments in a short wheelbase vehicle.

Can it be done? Yes. But probably not the results you will be expecting.
This is one of those projects that if you have to ask how to do it, you probably should be attempting it. You are not adding value, but you will be hurting it. It was done back in the day mostly because it was built out of parts that were just laying around. Working with cheap junk. I've even seen a Bronco running around (ok, never actually seen it run but can tell that it had) with a 223 I6 swapped in. Unique, yes. Desirable, it was for a parts truck. It was the last Bronco I saw come in to get parted out as the values were going through the roof. It would have been worth more with the original engine even if that engine was blown up.

 

[toddz69]

I've even seen a Bronco running around (ok, never actually seen it run but can tell that it had) with a 223 I6 swapped in. Unique, yes. Desirable, it was for a parts truck. It was the last Bronco I saw come in to get parted out as the values were going through the roof. It would have been worth more with the original engine even if that engine was blown up.

It sounds like you're describing this truck? I found it at a farmer's place near Coolidge back in '97 and about 16 years later it showed up at Randy's. There were 4 EBs on that farm - including the Peter Rabbit Stroppe Baja, which survived.

Todd Z.

 

[67sport]

It sounds like you're describing this truck? I found it at a farmer's place near Coolidge back in '97 and about 16 years later it showed up at Randy's. There were 4 EBs on that farm - including the Peter Rabbit Stroppe Baja, which survived.

Todd Z.

Well now THAT is a hood scoop!

 

[Timmy390]

Well now THAT is a hood scoop!

You speak the truth

Tim

 

[SLC]

Thanks guys I really appreciate your time and input on this…probably going another route.

 

[Broncobowsher]

It sounds like you're describing this truck? I found it at a farmer's place near Coolidge back in '97 and about 16 years later it showed up at Randy's. There were 4 EBs on that farm - including the Peter Rabbit Stroppe Baja, which survived.

Todd Z.

I'm sure that was it. Never seen the picture with the hood on. I remember seeing it hoodless and how tall that engine was.

 

[bmbm]

The 250 is easier.

 

[chrlsful]

nxt one I do would B the 4.9/300 (down’n back) for the same I went thru w/the 4.1’n NV U got bm.
Total opposite of post #12. Of the 4 I had (went thru them in early - late 8os to collect enuff to make this’un)
its my fav...
I went down’n forward w/this one, 4.9’d B back (ThriftPower i6 is not only long, is hi deck). These 2 more’n the 2.8 & 3.3 ford put in the bronk.

 

[DirtDonk]

Wondering if anyone has installed a 300 straight 6 Ford engine…

What was the original instigation for wanting a 300?
Finding them inexpensive? Looking for something different for a project? Or hoping for some other advantage?
The V8 swaps and/or upgrades are almost always a much better bang for the buck. And result.

 

[bigmuddy]

Plentiful, cheap, hard to kill and more torque than the 302 as I recall.

Local buddy has been working on one for a while but he is going to cut the front crossmember to lower the engine.

 

[DirtDonk]

Not as far as I remember.
I don’t know the power numbers for all years, but 260 pound feet comes into mind at the moment. Which is not as much as a 302, but might be about the same as a 289. Certainly not a 351.
Was probably more for the later model Efi versions though.
I imagine it just happens to come in earlier and peak earlier as its main claim.
But I don’t believe it peaks at more than the V8.

 

[bmbm]

I like all Ford products and have owned several 300s and currently own a 300/F150 in my former construction company material hauler and demo truck. Good low end torque. If the Bronco engine bay was a few inches longer Ford could have included the 300 as an option. I was considering the 300 before I did the 250, which has been really good, but the 300 swap was beyond my skill level and I would rather drive it than work on it.

 

[Timmy390]

Ford 300 Specs.... https://www.f150hub.com/specs/ford-300.html

Got to love the max torque at 2000 RPM 1600 RPM in the older models.....

Tim

 

[chrlsful]

yes, for the eqrlier tq.

For me? look at the inherent design difference by view from facing the crank snout. C the firing on circle radius of each motor. No
wonder the 3 is ‘internally balanced’ while bent8 hasa 34, 50 oz balancer, slugs on the fly wheel I hada grind off for my i6. The oomph of the piston explosions happen more equally around that circle, the tires have less slip in off rd conditions cuz the tq comes on @ lower RPMs.

The 4.9 is called both: ‘The gasser that’s a diesel’ & “ The million mile motor” along w/ OM617, & 170/225. W/the stevens HD ex manifold they ran Class 6/7 trucks (F650/F750) dump trucks in the 20 - 30K lb range. To me a better idea than even the 4Bt (1/2 a 12v) due to the weight alone~