Any 351W rebuilder gurus help a newb

[guidoverduci]

Lately I had been considering swapping out the 351w for something more… let’s just say ”shiny and new” But I forgot the PO of this bronco had given me a folder of work that he had done while he owned it for 15 years. I’ve owned it the last 4. I decided to go through, and I have found a ton of good nuggets, never realizing all the work that had been done. It appears the 351w was either rebuilt or swapped in, but I don‘t know enough about engines to decode this worksheet I’ve attached. Can anyone help me out and tell me a little about what I’ve got?

Some things I notice…
It says 1992 for 1973 Bronco. I’m assuming that’s when the motor was originally built. It says late block, one piece rear main
It lists a Crane performance Camshaft.
I think I see Bore 4.030.

I’m guessing all this means performance upgrades. I now thinking I should keep what I got and get a better tuned carb on there. It’s got an edlebrock currently, but it’s finicky. I’d like to have a Quadrajet ordered and built to go with my engine, but I’m unsure horsepower or what kind of performing engine I have Lol. And those are questions the carb builder is asking.

 

[Broncobowsher]

That looks like a nice street engine. Don't know the head castings, but from what I can tell it is probably just a set of stock heads that came with the engine that got a rebuild. Flat top pistons should make for a nice bump in compression and make it run a lot better than the stock dished I would expect for that engine.

I am going to say you are probably right, probably a 92 engine that was dropped off at a machine shop and had a lot of good parts put in it. Shame the date on the reciept got blacked out. It would have been nice to know when the work was done. A lot of this stuff you can put a vintage of what was popular and available at the time if you know when it was done.

The ARP rod bolts are a nice touch. Cast pistons tell me it wasn't planning on getting abused hard. If the valve springs can take it, should rev out nicely a bit past 5000 RPM. The springs spec is a bit weak, but the lifter spec says good.

I see they listed an all metal Holley 750 but you say it has an Edlebrock carb on it. Sounds like a post build change.

Looks like all good stuff put into the engine. Do note the firing order is NOT a 351 firing order. It is the old 302 order.
That engine should put out a solid 250+ HP and 300 torque on the low side. Well tuned add 25 to those numbers.

One thing I don't see is anything with the ignition. No idea if the timing curve of the distributor is anywhere close to correct. That engine is far enough from stock, a stock distributor curve just isn't going to cut it.

When you think you have a carb problem, it is probably ignition.

 

[guidoverduci]

That looks like a nice street engine. Don't know the head castings, but from what I can tell it is probably just a set of stock heads that came with the engine that got a rebuild. Flat top pistons should make for a nice bump in compression and make it run a lot better than the stock dished I would expect for that engine.

I am going to say you are probably right, probably a 92 engine that was dropped off at a machine shop and had a lot of good parts put in it. Shame the date on the reciept got blacked out. It would have been nice to know when the work was done. A lot of this stuff you can put a vintage of what was popular and available at the time if you know when it was done.

The ARP rod bolts are a nice touch. Cast pistons tell me it wasn't planning on getting abused hard. If the valve springs can take it, should rev out nicely a bit past 5000 RPM. The springs spec is a bit weak, but the lifter spec says good.

I see they listed an all metal Holley 750 but you say it has an Edlebrock carb on it. Sounds like a post build change.

Looks like all good stuff put into the engine. Do note the firing order is NOT a 351 firing order. It is the old 302 order.
That engine should put out a solid 250+ HP and 300 torque on the low side. Well tuned add 25 to those numbers.

One thing I don't see is anything with the ignition. No idea if the timing curve of the distributor is anywhere close to correct. That engine is far enough from stock, a stock distributor curve just isn't going to cut it.

When you think you have a carb problem, it is probably ignition.

Wow, thanks! Great info! Yeah, I wish the PO didn’t black out the date, seems silly. It’s got an HEI distributor with a red cap. There’s paperwork for something called the Holley Annihilator Ignition and crank trigger kit, but I don’t see anything around the engine. There’s a registration card associated with the Holley Annihilator that says the 351w is roughly 400 HP. Not sure where he got that #.

 

[guidoverduci]

Oh.. and it fires right up. Quick, even on cold mornings after it’s been sitting or weeks. Some of the issues are when I give it heavy gas, occasionally it will sputter. Today it popped out of the carb when I was giving it gas to back it out of the garage.

 

[SteveL]

Jet performance sells nice q-jet carbs. I think they're down in Huntington beach

 

[rjrobin2002]

Buy you some aluminum heads and throw them on if your bored and want a 50-100hp gain while your tinkering.

 

[bmc69]

Speaking as a builder...that's a very thorough and professional list of things done to that rebuild. Wouldn't get all that done for those prices today! ;-)

 

[Broncobowsher]

Oh.. and it fires right up. Quick, even on cold mornings after it’s been sitting or weeks. Some of the issues are when I give it heavy gas, occasionally it will sputter. Today it popped out of the carb when I was giving it gas to back it out of the garage.

Pop out the carb on a cold engine, generally a choke setting too lean.

 

[guidoverduci]

Pop out the carb on a cold engine, generally a choke setting too lean.

The other thing, ever since I’ve owned it, it fires right up when cold, no matter how long it’s been sitting. Then I drive it for a bit, get it warmed up, run into a store, and when I come back out to start it again, it always takes a bit. Like the starter is tired or something.

 

[Broncobowsher]

Sounds like a carburator. Boils the gas off and down the engine when you shut it down. The long crank is basicly clearing a flooded engine.
That is what got me to give up on carburators and go EFI. Didn't change the driving or fuel economy, but was able to fix the hot restart and cold drivability. Got a better timing curve and that helped a lot with power.

 

[guidoverduci]

Sounds like a carburator. Boils the gas off and down the engine when you shut it down. The long crank is basicly clearing a flooded engine.
That is what got me to give up on carburators and go EFI. Didn't change the driving or fuel economy, but was able to fix the hot restart and cold drivability. Got a better timing curve and that helped a lot with power.

Ahh.. that makes total sense! I’ve actually been meaning to move my fuel lines around because they are real close to the exhaust. Probably another contributing factor.

 

[DirtDonk]

Why did you want to change it in the first place? Just to make it shiny and new? Or do you think it lacks power and is not running right?
Probably needs a full tuneup and verifying proper tuning specifications.
Also, how many miles on the engine? I’m curious if the engine builder, or the installer, or the previous owner broke in the cam properly.
That would be a bummer to have all that and shoot yourself in the foot on the first start up.

But just as important as all those other questions and power assumptions is tire size and gear ratio and transmission.
What transmission are you running, what gear ratio in the differentials, and what tire size?

 

[guidoverduci]

Why did you want to change it in the first place? Just to make it shiny and new? Or do you think it lacks power and is not running right?
Probably needs a full tuneup and verifying proper tuning specifications.
Also, how many miles on the engine? I’m curious if the engine builder, or the installer, or the previous owner broke in the cam properly.
That would be a bummer to have all that and shoot yourself in the foot on the first start up.

But just as important as all those other questions and power assumptions is tire size and gear ratio and transmission.
What transmission are you running, what gear ratio in the differentials, and what tire size?

I’d call it a combination of wanting modern EFI, AUTO, shiney and new, and the bug to give the bronco an upgrade. It actually runs pretty good, but you’re right.. probably could use a fulll tuneup. Not sure how many miles, I couldn’t imagine a ton. I’m guessing the rebuild was in the early 2000s and the 2 prior owners didn’t use it as a daily driver. The guy I bought it from barely drove it and it was the guy before him that had all the engine work done.

The transmission is another reason I was looking to upgrade. It’s a 4 speed manual. There’s a receipt for that swap too from a shop, but on one spot they call it T170 and another T176. They are very similar looking, but I believe its the T170. Ratios on that one are 1st=3.0061, 2nd=1.7767, 3rd=1.0000, and 4th=0.724. Tire size is 35” and gear ratio Is 4.56. I’ve also been considering just updating the trans to a NV3550 or AX15, but not sure if it’d give me a change that’s worth the cost. And having a manual is a lot of fun, but loved my last bronco that was an Auto. I go back and forth with the manual or auto decisio too lol.. I’m all over the place