rebuild 302 or swap in 351?

[wap13]

Ok Adam, I'm here now!


So the stock computer system is very basic and can barely compensate for 10% +/- airflow differences. So you would have to use a 351 computer if you swapped in a 351. The 302 computer could not support the fuel requirements for the extra displacement. Keep in mind that none of the truck engines from this time period were hot rods. They have one job and that was to haul loads reliably. Speed of hauling was last on the list.


I have been driving an 88 f150 300 5 speed daily for almost 6 years now. It keeps up with traffic just fine and hangs with everyone on the highway too. It is the lowest hp engine at 150hp brand new! The 302 has a bit more hp, I think 165ish? But shares the same torque at 260ft-lbs with the 300. The 300s have their weaknesses though. Everybody lugs the *s-word out of them because of their high torque at the expense of the bearings. High load at low rpms means low oil pressure and premature bearing wear. There are also 13 bearings on the crankshaft. That is a lot of areas for the pump to lubricate. Good rule of thumb is to keep it over 1500rpm when driving and you will have plenty of oil at the bearings. Here are the bearings out of my original engine with 112k on them! Grandpa liked to lug it.

View attachment 346930

This is the info I was looking for. Thanks. The ecm is no big deal cost wise if I go with a 351. And I am not looking for a hotrod, just something to cruise around offroad in. Hardly ever would it see 3k rpms. Someone mentioned a shift kit.... its got a zf5 in it so I got the shifting (and low end) gearing taken care of.

Thanks for all the replies. Got a line on a 351, a complete van actually. If I can get it cheap enough I will. Other wise I will likely just put a short or long block 302 in it depending on what I come across for heads. I still need to talk to my machine shop to, to get some prices.

Still would really like to have a 300 one day but I dont see the swap being worth the effort in a efi truck. It I was g0ing carbureted I would think harder about the 300.

 

[Steve]

This is the info I was looking for. Thanks. The ecm is no big deal cost wise if I go with a 351. And I am not looking for a hotrod, just something to cruise around offroad in. Hardly ever would it see 3k rpms. Someone mentioned a shift kit.... its got a zf5 in it so I got the shifting (and low end) gearing taken care of.

Thanks for all the replies. Got a line on a 351, a complete van actually. If I can get it cheap enough I will. Other wise I will likely just put a short or long block 302 in it depending on what I come across for heads. I still need to talk to my machine shop to, to get some prices.

Still would really like to have a 300 one day but I dont see the swap being worth the effort in a efi truck. It I was g0ing carbureted I would think harder about the 300.

Be careful about a van engine. The intake manifolds are different than the trucks and the manifolds for the 302 and 351 are different too.

I would personally stick with the 302. A fresh engine will run like a 351 vrs. Your worn out engine. You already have the 302 set up. The 351 may be pinned differently at the EEC too. Study your wiring diagrams close.

 

[timg]

I've got a carbureted Crane cam kit new in box ( low end torque and RPM) and an intake if you go with the 351m assembly. I can be reasonable.

 

[Maintenance Chief]

Any thing for the 351m would also work with the 400 modified.
351 heads with bolt on a 302 also.

 

[timg]

Any thing for the 351m would also work with the 400 modified.
351 heads with bolt on a 302 also.

The main thing with the 351 windsor is the distributor and firing order. It's a beast of it's own.

 

[wap13]

I have a hard time leaving anything well enough alone for the sake of performance BUT I think I will likely just stick with a 302. I keep looking at cams and gt40 heads etc but keep talking myself out of it. I have a land cruiser project going too and I really just need to get my old f150 back to firewood duty and what not. A drop in 302 is for sure going to be the easiest quickest thing and most likely cheapest too.

Thanks for all the replies

 

[timg]

I have a hard time leaving anything well enough alone for the sake of performance BUT I think I will likely just stick with a 302. I keep looking at cams and gt40 heads etc but keep talking myself out of it. I have a land cruiser project going too and I really just need to get my old f150 back to firewood duty and what not. A drop in 302 is for sure going to be the easiest quickest thing and most likely cheapest too.

Thanks for all the replies

I hear ya on the heads and of course intake, the list and money only gets deeper.
But the cheapest bang for your buck regardless of whats above it is a cam kit. Great results with minimal investment not matter what engine you go with. Anything but a stock bump stick LOL!!

 

[Steve]

I have a hard time leaving anything well enough alone for the sake of performance BUT I think I will likely just stick with a 302. I keep looking at cams and gt40 heads etc but keep talking myself out of it. I have a land cruiser project going too and I really just need to get my old f150 back to firewood duty and what not. A drop in 302 is for sure going to be the easiest quickest thing and most likely cheapest too.

Thanks for all the replies

Be careful with the performance cams. The stock eec can't handle them. Also you will loose your drivability as a work truck. That is why I ultimately decided to just go stock on my 300. Which I guess is technically a 305 now that it's .030" over!

 

[Maintenance Chief]

Compu-cams sells computer friendly cams.

 

[Steve]

Compu-cams sells computer friendly cams.

They sure do. But the first gen MPI fords don't like them.

 

[Kiwioilboiler]

They sure do. But the first gen MPI fords don't like them.

Not enough Atari 64s to calculate the new airflow?

 

[Steve]

Not enough Atari 64s to calculate the new airflow?

Yup. The EEC in these is not self learning. It just reads off a base map and easily falls out of closed loop operation.

 

[wap13]

Yeah, I understand on the cams. AND even if they played nice with the ECM theres not a lot out there for low end torque, esp for a 302 that likes to spin.

Like Steve said I bet a new 302 will feel like a 351 to me.

As mentioned I got the truck 3rd hand, I'm sure maintenance was shoddy at best and it had sat in the woods for a year before I drug it out and got it running. That was at least 12 years ago. I did put head gaskets in a probably 5 years ago but other than that its just gotten oil changes.

Getting a trans with a proper 1st gear made a huge difference. Honestly if I handnt gotten the zf5 years ago I would not bother resurrecting the truck.

 

[Steve]

Yeah, I understand on the cams. AND even if they played nice with the ECM theres not a lot out there for low end torque, esp for a 302 that likes to spin.

Like Steve said I bet a new 302 will feel like a 351 to me.

As mentioned I got the truck 3rd hand, I'm sure maintenance was shoddy at best and it had sat in the woods for a year before I drug it out and got it running. That was at least 12 years ago. I did put head gaskets in a probably 5 years ago but other than that its just gotten oil changes.

Getting a trans with a proper 1st gear made a huge difference. Honestly if I handnt gotten the zf5 years ago I would not bother resurrecting the truck.

You must really be doing some hauling with that truck if you needed 1st gear from a ZF5! Usually I just start off in second from a stop. Those should really be called a 4 speed with low! What is your final drive ratio in that truck? Most 4x4 trucks of that era came with 3:55.

 

[wap13]

You must really be doing some hauling with that truck if you needed 1st gear from a ZF5! Usually I just start off in second from a stop. Those should really be called a 4 speed with low! What is your final drive ratio in that truck? Most 4x4 trucks of that era came with 3:55.

Not at all really. I do heap it up with red oak a few times a years. Kind of surprised the 8.8 has held up but I also dont drive it like an a hole loaded that way. I do haul heavy but I have other heavier duty trucks made for that and am working on getting a low boy.

I am off road more than most and thats where the low gears come in. Its really nice to be able to idle up a hill, across a creek, off with a load of wood, etc and just let the truck chug a long without having to kill the clutch,stall out or be doing 10mph at an idle with (was it 3.75) first of the m5od. I doubt I will ever put the money into it but if a set of 4.56s or 4.88s ever fell in my lap I would install them in a heart beat.

Its a 3.55 truck. With the m5od low range was a must once I pulled into a pasture if I just wanted to putt along. Remember too I dont have 300 like yourself. This 302 needs all the help I can get.

I'm going to go ahead and order all the stuff I need like water pump, t stat, slave, etc. Once that gets here I'll order the long black as I can have it in less than a week. Prob just going to let my local shop do it for me. He does all the stuff I dont have time for. I have 2 sets of studs to put in 6.7 dodges on top of all the other tractors, equipment and implements I have to work on. Some times its cheaper to pay somebody and hes a friend of mine. Plus with him doing it I get a 3 year unlimited mile warranty on the crate engine so its cheap insurance too.

 

[Steve]

Not at all really. I do heap it up with red oak a few times a years. Kind of surprised the 8.8 has held up but I also dont drive it like an a hole loaded that way. I do haul heavy but I have other heavier duty trucks made for that and am working on getting a low boy.

I am off road more than most and thats where the low gears come in. Its really nice to be able to idle up a hill, across a creek, off with a load of wood, etc and just let the truck chug a long without having to kill the clutch,stall out or be doing 10mph at an idle with (was it 3.75) first of the m5od. I doubt I will ever put the money into it but if a set of 4.56s or 4.88s ever fell in my lap I would install them in a heart beat.

Its a 3.55 truck. With the m5od low range was a must once I pulled into a pasture if I just wanted to putt along. Remember too I dont have 300 like yourself. This 302 needs all the help I can get.

I'm going to go ahead and order all the stuff I need like water pump, t stat, slave, etc. Once that gets here I'll order the long black as I can have it in less than a week. Prob just going to let my local shop do it for me. He does all the stuff I dont have time for. I have 2 sets of studs to put in 6.7 dodges on top of all the other tractors, equipment and implements I have to work on. Some times its cheaper to pay somebody and hes a friend of mine. Plus with him doing it I get a 3 year unlimited mile warranty on the crate engine so its cheap insurance too.

Gotcha.


It's not a jasper rebuild is it? We quit using them. Have had to replace almost half the engines I've installed and had to put 3 reman axles in one jeep due to whine noises before I convinced the manager to just let me rebuild it.

 

[wap13]

Gotcha.


It's not a jasper rebuild is it? We quit using them. Have had to replace almost half the engines I've installed and had to put 3 reman axles in one jeep due to whine noises before I convinced the manager to just let me rebuild it.

No sir. I've only dealt with 1 jasper. It was a 360 in a wagoneer that wasnt mine but it did ok. However I have heard they aint what they used to be.

It's a napa "ironclad" but atk builds those. So far I have hear nothing but good things about them and I have a good relationship with my local napa so IF there is a problem in 3 year warranty period I dont see any issue.

Glad to see someone else on here will set up a R&P. I've only done a few but trying to find someone do it around here is rare as hens teeth.

 

[Steve]

No sir. I've only dealt with 1 jasper. It was a 360 in a wagoneer that wasnt mine but it did ok. However I have heard they aint what they used to be.

It's a napa "ironclad" but atk builds those. So far I have hear nothing but good things about them and I have a good relationship with my local napa so IF there is a problem in 3 year warranty period I dont see any issue.

Glad to see someone else on here will set up a R&P. I've only done a few but trying to find someone do it around here is rare as hens teeth.

Good relationships with business's are critical. I wish more people would practice that. Yup, setting up a r&p is no big deal. Especially if you use new gears. The 8.8 in my f150 now was challenging as I built it from all good used parts. Trying to get the correct pattern when the gears already have wear pattern was very trying!

 

[redline4]

Not going to get a good pattern from this one..

 

[Steve]

View attachment 347107

Not going to get a good pattern from this one..

That's because you work at a GM dealer...