Hi everyone,

I am brand new to the forum! Been reading everything I could find on swaping a 351m to a 460... Truck is a 78 F150 4X4 with granny 4 speed trans....

I got past some small bumps and now I am having my first big major problem. We got the motor in place tonight and the basics hooked up. We hit the key and the motor went about a quarter/half rotation and seemed to seize up. Now the starter will not turn the motor. Everything seemed to slide together ok once it dropped into the mount perches. But now every other time I hit the key the motor only moves about an 1/8th inch. I loosened the trans bolts up at the Bell opened a small gap hit the Key and still same problem!


Here is the list of what I installed.... (Keep in Mind I am not a mechanic) so please talk in lamens terms and pretend I am stupid LOL

Internaly Balanced 78 or older 460 (According to the block casting #)

My Original 351m Bellhousing, Opened up the Tin shield to clear the crank.

302 Pilot bearing... and drove it in as far as it would go into the second register (Deepest) in the crank. The bearing did have a very slight lip on it and I have know way of knowing how deep it is suposed to go in there.

184 tooth 352/390 flywheel neutrally balanced, from Jegs... Part #555-601370

Clutch mounting holes did not line up like they promised for my stock 351m 11" Clutch, so I took it to a machine shop and had them drill/tap it for my existing clutch and preasure plate assembly.

Transdapt 460 swap motor mounts.....

Re-used my 351m starter. It seems to engage the flywheel perfectly.... I would think it would be strong enough to turn it but have now idea how old it is.

We put the truck in the air and put a 1/2" drive ratchet on the front of the crank, used a pipe for leverage and we cannot turn the motor clockwise!

I am hoping there are some things other than assuming I have a locked up motor that I can eliminate before we go through pulling this thing back out and opening up the motor! Not sure how long the motor sat but suposedly came out of a running small dump truck.

Anyones help/Ideas here are greatly appreciated!

Have a blessed Week!

Rick

 

did you buy a used motor that was sitting? turn it over by hand on the floor to see if it turned? pop the valve covers to see if there is any rust,dirt ect? see condition of oil? thats the 1st things i would have checked a buudy had that problem 2 with a dodge 360 that sat for a year removed the spark plugs spray wd40 you may break it free good luck

 

Pull the plugs then try to turn motor. If it turns your ok there. Then drop your starter then try to turn motor. If it turns without the plugs you are fighting compression. If it doesn't turn until you drop the started your starter is seized.

 

Thank you guys I apreciate the replys. I will try these things tonight after work and let u know.

 

Disclaimer: I haven't done the swap... yet, I've done a bunch of "research" and I'm acquiring parts to do it.

It's my understanding that the 460 bell housing is deeper than the 351M/400 bell housing. Some people make a spacer plate between the block and the bell housing, others just buy the kit from L&L, and another option is to use a 390 flywheel (if the 460 was an internally balanced version). The machining on a 390 flywheel is different and positions the flywheel closer to the block than a 460 flywheel.

In terms of the parts you used:

I haven't heard of using a 302 pilot bearing in the 460 crank. I think most folks purchase the L&L pilot bushing.

My biggest concern is the clutch pressure plate. When I've done research on the swap everyone seems to use a clutch set-up for a 390. I'm concerned that the 351M pressure plate cover is contacting the inside of the bell housing and that interference is the cause for the binding.

There are different "styles" of clutches. I think the oem 351M is a "Long style". Based on my research I was planning on using a diaphragm style for a 390 engine.

Again, I haven't actually done the swap so take my ideas with a large grain of salt...

 

This was my thought too, I just did a 400 to 400 swap and tryed to use the older 3 arm clutch. it hit the clutch fork and would only let engine turn a 1/4 turn, changed to the diaphram clutch, no more trouble. look in the clutch fork hole and you should be able to see if this is your trouble!

 

i did this swap in my 77 except its got a C6.... only thing i changed was the torque convertor and the engine.... used the 460 flywheel and the 351m starter!


*** only changed convertor cause i went with a small stall***

 

The bell housing on the 351 and 400 needs to be swapped out when converting to a 429 or a 460.

There is a spacer that can be found to make up the differance in clearance that the 400 bell housing can be used. Six states clutch in salt lake city had one made that they sell (aka exchange parts ask for mike 801-485-2474).

I am having problem repairing a clutch in a truck I bought as it turns out I have the wrong bell houling and the clutch disk was binding up on the part of the transmition the shaft comes out of.

My Casting number on my bell housing is E1TA7505-AA I am new here to I came on here just for this problem. I have not had much sucess. I was told by a parts person at the ford truck land her in salt lake city that my bell housing went on a 400 if you happin to find out what the cast number on your bell housing I would be very interisted in finding out what it was.

I hope this helps.

 

I tryed to used the 351-400 flywheel bolts and they were too long, locked the motor up just like you said. I had to use the auto's flex plate bolts.

 

Thank you very much guys!

Depending on my work schedule today I will be trying to go over and check all of this out! Unfortunately the truck is not at my house.

Hopefully after that I can post what I find..... Not being a mechanic makes it difficult but I am sure I will work throgh it LOL..... Just praying this motor is good and I will definately be checking the contact with the bell first. I thought I followed the list exacly but you know how that goes....

Everyones responses are greatly appreciated and thank you to all.... Keep the ideas coming!

 

I have talked to a few people who claimed to have done a number of these conversions and the related theme is if you use a 390 fly wheel and machine off about 1/8 inch there are no clearance problems. I am in the process of finding a 390 fly wheel if it works I will let you know.

The discrioption geven by the people who mad the conversion without using a 390 flywheel or machining of a small amount it locked te engine up simular to how you discribed it. However, I don't have first hand knowledge.

 

Thanks jon73! I will also look for the casting # on the bell for you when i get back to the truck.... not sure if i will be there tonight or tomorrow.

 

Ok Guys i got to spend a little bit looking at this thing tonight, looked up in the bell and man does the flywheel look close at the top maybe hitting not sure yet.... borrowed a fiber optic camera and the head on the darn thing was just a bit to big to get in there and see whats going on....

Work and kids are more important at the moment so I am hoping to put some time into it this weekend... gonna drop trans etc. get the bell off and see if she turns free after that... wish me luck and again thanks for all of the ideas guys! Been a big help thus far!

I will post what I find as soon as I can....

 

I did the swap from my 302 to my 460 this summer. Being the cheap *** i am, i reused everything i could. I am running the 390 flywheel with the 302 pilot bushing, an 11 inch clutch from summit, the atarter alignment plate from a 400 with the center cut out, and a 400 bellhousing. I have had none of the clearance issues that are stated on this thread. The only snag i had was finding the 400 clutch bracket that hooks onto the bellhousing instead of the block.

 

Well....here's what I did:

Internal ballanced 460
390 flywheel neutral ballanced
Clutch for a 1975 F150 w/ 390 (I used the pilot bushing in the kit)
Starter from the 460 (or 400...I can't remember)

I slapped it together and all is working fine for now.