I have a 91 F150 4x4 EFI. The motor thats in it is a 302 HO that came from an 86 (I think) Mustang. After this hunting season it has to be pulled and gone through. I want to add some HP to it while its out, cam and heads. Here is my dilema. I think I can get my hands on a 351 Modified out of a 78 F150.

So I have 2 questions here:

1. What is the best route to go with the motor situation? Stay with the 302 and build it up some or go with the 351M (if its even compatable) and go through it.

2. The E40D tranny is horrible in it. I have had it rebuilt 2 times already and it still sucks. Off the top of your head what is the best option with either of these motor set ups?

Thanks!

 

I say Windsor all the way. If your tranny is having problems with that 302 than I am thinking it would have a lot more trouble with a 351 turning it. If you can get your hands on a beefier tranny, then a 351 would put out more power and be cheaper than building the 302 (assuming that the 351 doesn't need rebuilt). But then you are adding the expence of the tranny and the 351. If it were me, I would do a mild build on the 302 and look into a different tranny. Just my thoughts on the situation. also, I read somewhere that all small block fords share a bellhousing, so the motor should bolt right to it.

 

<span style="text-decoration: line-through;">From what I've heard, when the motor goes, the transmission is surely soon to follow.</span>

Edit: I guess my personal experience isn't a broad enough sample to draw a conclusion from. I have been contradicted by a user below. For these reasons, I retract my above statement.

 

Yeah, the tranny has to go for sure either way. I do not want to have it rebuilt a 3rd time. I read that the E4OD is NEVER right after its rebuilt.

 

I would go the route of the 302 and just look to swap the tranny out. A rebuilt 302 will be a fun project and you can go any route, Crank, cam, pistons, etc.

 

I am in a similar situation except I am replacing the worn out 351w in my ‘90 with a slightly used 351 out of an ‘87. The E40D is starting to slip and giving me trouble as well. It has over 300,000 miles on it now (I think) so I am certain that it is about to go and I was thinking that I would have it rebuilt. Since you have experience in this, why would you not want to have the E4OD rebuilt and what transmission are you thinking about replacing your E4OD with? I was curious what you heard/had experience with on rebuilt E4ODs? The 351 I bought came with a C6 bolted up to it.

 

Rebuilding an E4OD if done right is fine. I have a friend who builds transmissions daily, he speaks highly of the E4OD. The problem lies in the build and what you pay. There are some shops out there that ONLY replace what is broken, or causing problems at that time, some dont even change internal gaskets/seals. IF you are having your trans rebuilt, and you want to keep it for a while. Have the shop make sure they go through clutches, seals, and valve bodies. On the E4OD there are updates from sonnax for the acumulator body, and the valve body, these help greatly. Personally I was once scared of the E4OD and heard all the horror stories. They are very tough transmissions if they are taken care of.

 

Not true. The 351M uses a different bellhousing pattern than the 302/351.

This is just nonsense.

Not true either. Where are you guys getting all this???

Personally I would go with a 351w. There is no sense in spending a lot of money on aftermarket goodies for a 302 when you can start with more power and more low-end torque from the get-go with a 351w. You can spend the same amount on a 351w and end up with 150+ more horsepower. It's a no-brainer if you ask me.

As far as the tranny, an E4OD when rebuilt by a competent shop is an excellent tranny that will last a very long time. You get what you pay for though. A good rebuild is likely to cost $2500 to $3000 depending on what needs to be replaced.

If gas mileage is a concern you probably want to go with the E4OD because of the overdrive and locking converter. If you don't care as much about gas mileage and are looking to save money in the short term you can't really beat the toughness or price of a C6.

 

Andym,

Thanks for clearing some of this up.. I was really at a loss for some of the speculations.

 

The M is not compatable so forget about it, get a 351w or just upgrade the 302. You're limited on what you can do though because of the SD EFI and fuel systems, you could get away with some GT40 heads and an exhaust but that's about it. That would be a healthy step up from where the motor is now though, the E6SE heads used on the '86 HO were the worst flowing version ever.

What about the trans is horrible? What size tires and gears does the truck have? Are there any codes present? The E4OD is comtrolled by the EFI computer so any major sensor fault will affect it's operation.

 

@ andym... If it WAS a 351w I would agree with you.. but it is not.. as he stated it is a 351 modified. So in this situation I would stick with a 302 H.O. built. That is a no brainer to me.. the windsor's reliability is hard to ignore.

 

I know it's not. If I were OP I would find a 351w.

 

I wound just spool up the 302 , it will do what you want with some work ....Lew

 

Oh I see what your saying now andym, my regaurds. And concerning the issue at hand, I say do whatever you are most comfortable with. You know what you are capable of better than we do, you know where your comfort zone is and you know what you are wanting out of your engine. I am thinking that no matter what route you take you are going to be happy. I have a 351w 4x4 and it is my favorite truck. My dad owns a 302 4x2 and I drive it all the time as well. The 302 is a little gutless for farm work, but it is still a great DD. The 351 pulls like a mule, but gets about 12mpg unloaded and is completely stock. Both trucks are f150's (I know, neither of them should be pulling heavy trailers, but its what we have, its what we use). If you are looking for a tire-frier than beef up a 351 (perferably a Windsor), if you are looking for a DD that can smoke any civic on the street, then beef up the 302. Like I said, its all about what you are comfortable with, you can't really go wrong here. The only wrong you can do is let that truck sit without an engine in it, and you have already proven that is not going to happen by showing intrest in rebuilding or replacing, and by asking for some decisions. Sorry about the rambling, I do it a lot. Hope something I said can help you out. And also, thank you andym for clearing up the bellhousing comment I made, the last thing I want to do is hand out false information.

 

The motor I can get is a 351M so as you guys have made clear I will forget about that one. I will loolk around and see what a 351w goes for but not sure what the purchase cost would/should be for the motor. I already have headers and exhaust on the 302 the next step was/would be heads and a more aggressive cam unless you guys threw some better options at me, which you are doing.

The tranny drops hard into gear, sometimes shuts off when you drop it into R, jumps hard from 1st to 2nd and a jumps a little from 3rd to 4th. Last rebuild cost me $2k and didnt last long. I have 4.56 gears front and rear in it. It runs 38.5x15x15 Super Swamper Boggers. This is a hunting truck not a DD. I know with those tires its very abusive on a tranny but thats why I am asking you guys that know so much more than me what direction I need to research. C6, a better shop to rebuild the E4OD...etc. I have read lots of posts on various sites where people talk about the E4OD never being right after a rebuild. I have had 2 good local shops rebuild and I am 0-2 on a good tranny after rebuild.

Again, thanks guys I am doing research here and this is some top notch info for others to come by as well.