351 EFI or 302 EFI?

[zdaily]

I bought a 74 bronco the other day, it's a pretty sweet ride. Cage 5.5 lift and radius arms, 2 inch BL, 4.88 gears, 37 Boggers, Ox Locker and Detroit in rear. Awesome rig, only thing is the engine is getting weak, it's just a stock 302. The guy I bought it from gave me a 351W out of a van with about 70,000 miles on it and he gave me a 302 EFI out of 91 Mustang. I was thinking about combining the two, put the EFI on the 351. However, I might need to freshen the 351 up a bit, so I was thinking about doing a basic rebuild keeping it pretty much stock.

Does anyone have a preference on what engine they'd go with? I definitely need fuel injection, just not sure on motor. I just did a 302 EFI setup in my 66 and absolutely love it, but it's still a little weak on low end.

Any advice would be great!!

 

[Devin]

No replacement for displacement. Go with the 351.

 

[mlogan24]

Ditto for above-351.

 

[fordguy]

what is the condition of the 302

 

[SaddleUp]

Sounds like you have the right plan. The 351 is going to build more torque and the Mustang EFI does a decent job on the 351 motors. (That's what most of us with EFI on our 5.8/351W motors run)

 

[mlogan24]

You'll need this to run the 302 EFI on the 351.

http://bcbroncos.com/store/product_info.php?cPath=131_108&products_id=1059

 

[zdaily]

Thanks for the feedback. The more I think about it the more I really like the 351 idea. Does the Mustang EFI system provide enough fuel / air for the bigger motor?

BTW, the 302 has around 80K miles.

 

[zdaily]

One other quick question, does anyone know of a great "lower cost" rebuild kit that will freshen up the 351 without making it too high performance? I found one on Summit for $369, that seemed like a good deal, comes with 9.17:1 pistons, etc. Here's the link:

http://store.summitracing.com/partdetail.asp?part=FEM-MHP176-311&autoview=sku

 

[bronko69er]

Thanks for the feedback. The more I think about it the more I really like the 351 idea. Does the Mustang EFI system provide enough fuel / air for the bigger motor?

BTW, the 302 has around 80K miles.

I'm guessing you'd want to upgrade for stock 302 EFI stuff.
You can size your injectors and MAF to any HP you desire.
I think 24lb injectors and a 75mm MAF would be what you need for a stock 351.
Am I right EFI guru's?
Maybe 30#ers?

 

[SaddleUp]

The stock 5.8 uses 19# injectors which is the same as the Mustang uses. I.E. As long as it is kept close to stock then it shouldn't need to be changed. (I still run the stock stuff in mine)

There are several intake options that can be used. My order of preference is as follows.
1: Stock truck intake. The truck intakes are set up to build torque while the car ones are set up to build more horsepower instead. For a Bronco (At least for me) I am looking more at torque than HP. The main problem with the truck intake is that it will not fit under an EB hood unless you cut it out and build a custom hood scoop for it. Even with a 3" body lift it comes 3 1/2" or so higher than the top of the hood
2: Edlebrock Performer EFI intake (Or similar aftermarket intake). The aftermarket intakes are usually tweaked for a specific RPM range and come out a little better on the Dyno than the stock GT40 ones do. For the cost they are often close to the same price as well so it's a better choice if a GT40 can't be found for a good deal.
3: GT40 5.8 lower with a GT40 style 5.0 upper. (GT40, Lightning, Explorer) These are a good option when a lower intake can be located at a reasonable price. Ford no longer makes this lower intake though and too many gearheads think they are worth their weight in gold so they drive the prices up to where they cost either as much or almost as much as the aftermarket ones. (Anything that approaches half of what the new aftermarket ones are is too much for me)
4: Adapt the truck lower to a car upper. (Link above) This is probably the cheapest way to do it but the car and truck runners are not the same so adapting it like this is going to mess with airflow. To be honest I really don't know how it will effect it so without Dyno figures I personally would make this the last option if another can't be found. I may actually give this a try myself just to see how well it works.

Number 2,3, & 4 can be made to fit under a stock hood however they will still need either a body lift or a higher aftermarket hood. (Or maybe both dependng on the hood and amount of body lift)

 

[Broncobowsher]

351!!!

37's are big tires
I am sure the rest of your truck is heavy as well.
As long as the 351 is kept stockish the mustang fuel injection should keep up just fine.

 

[Duke Nukem]

A stock 5.0 mass air EFI system will work just fine on a fairly stock 351. I run the same EFI system on my 351 that I used to run on my 302 and it ran both engines just fine. You don't need anything more than standard 19# injectors and other hardware with a stockish 351.

Based on SaddleUp's list I'm running option #4 and it works great. I have a stock 351W truck lower intake matched to a passenger car upper using a BC Broncos adapter. It is the poor man's 351W EFI setup but I have to say it works great.

I created a thread showing how I set up my 351W with EFI. Hopefully this helps: http://classicbroncos.com/forums/showthread.php?t=104631&highlight=EFI

 

[zdaily]

Thanks again for the feedback. For now I'm leaning towards the #4 option, using a truck lower, BC adapter, and car upper like Duke uses, RJM harness, etc. If anyone knows a good source for a basic rebuild kit for a 351, let me know.

 

[SpareParts]

I believe Chuck has the dyno results on his web site for option #4.

David

 

[wildbill]

;D ;D ;D Biger is better go with the 351W you will be happy good luck.;D ;D ;D Bill ;D