I'm getting ready to buy a 88-92 Bronco to tow a small camper and need a 351 engine. How can I tell if it has a 351 over the 302?

B

 

If just looking at the engine the 351W has basically the same block as the 302W just a slightly taller deck/wider intake. Not sure on exact measurements though... Don't know of any other visible differences...

 

Well the unmistakable difference is the intake manifold, the 351 is much wider than the 302, the deck height on the block is taller as well. I suppose if you don't have an engine savvy eye, then the easiest way would be to look at the VIN number under the windsheild on the drivers side, more than likely the owner would surely know which engine he or she has. One other difference is in the exhaust, most (but not all) 351's have a single large muffler with two tail pipes exiting on the passenger side were as the 302's have single tail pipe exiting in the same location. If you are unsure about the engine code, you can post your VIN on here and just about anyone will tell you what it is.

 

i have looked at several Broncos on dealer lots and they tend to say v8 or 5 oh! when i ask about what size motor. i don't think the average car guy knows that a 5.7 was even an option. Is there a certain option number on the VIN that would indicate a 351? I'll check the muffler next time I look at, but i have only seen single exhaust pipes so far.

Thanks,
B

 

Actually I think the 351's were always referred to as 5.8L, and yes, engine size is designated in the VIN... I'm sure someone on here can tell you which digit, and what letters are for what engines, but don't rely entirely on the VIN to tell you what engine's in it...

 

Here's an easy way that works for me on a quick look. Take a look at the lower bolt on the thermostat housing. If the bolt is behind the timing chain cover/water pump on a horizontal plain it is a 302. If the bolt is above the cover/pump it is a 351. If you could see these side by side one time you would be able to easily see the difference. Anyway that's all I got to say bout' that!

 

Any pictures of the engines? thermostat housing?

B

 

i could be wrong here, but if its an 88-92, then its going to be EFI, and the EFI manifolds have the liter stamped right on top, right? mine says 5.0 EFI and my dad's bronco ('96 351) says 5.8 EFI. that would be the easiest way to tell, since the manifolds arent interchangeable between the 2.

 

Oh, great we just about had this guy totally confused, and then someone comes along being logical...

Actually weren't some 351W's still carb'ed even as late as '87? I helped my buddy build a 351W for his '78 F100. The engine came from an '87 E150 if I remember right, and I'm almost certain it was carb'ed... but I was wrong once before I suppose it's possible I could be again...

 

Damn Donate, now don't we all feel silly.

Good call, didn't even think about that! (Too obvious I guess, huh)

 

MAN!! you guys crack me up. I was waiting for someone to come up with this obvious answer. I would guess 95% of the EFI vehicles out there have some sort of engine size printed in bold text directly in your face when you open the hood. Its advertising at work.

 

Anybody want the technical answer?
The 8th digit in the VIN number is the engine code

N = 5.0
H = 5.8

as in

1FM E U15 H 5 X X AXXXXX

 

I have checked the upper intake on several Broncos and all they say is "Electronic Fuel Injection". I have also looked at belt routing diagrams and emission stickers, but both list the specs for 302 and 351. Sorry about calling a 5.7. I long time ford guy like myself should have known better. I have my FLAME suit on, just in case! I looked on the Edelbrock site at their 302 and 351 intakes and both pictures look identical.

B

 

The 302 has a deck height of 8.205" and for the 351 it's 9.503". They can use the same upper manifold but have to have a different lower to accomodate the greater distance between the heads.

If the VIN number answer doesn't give you enough info, the 302 ia about 18-3/4" wide and 20-3/4" high. For the 351 those numbers are 21" W x 23-3/4" H

 

that's weird, ivenever seen any that just say that. anyways, in that case i think the easiest way to tell is to look at the vin number then, good luck