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I have owned this 78 f 150 2wd 351m for going on 7 years it always carried very low oil pressure less that 20 when warmed up. Today was the death of this tough engine it spun a rod bearing.. now what I have setting in the yard as of today is a 79 Ltd it has a 302 with a c 4 auto transmission. I have worked on cars and trucks since 1978 but never done this type of engine swap. I know the 302 will not both to the 351m belhousing. I want to drop this engine and transmission out of the Ltd right into my 78 f 150----can all you guys out there that have done this swap tell me what I need? like will the drive shaft fit?, and the transmission mounts? I dont do anything half "A" It has to look just like it belongs when the hood comes up also one other also is there monts for the old type ac compressor? the Ltd has what I call the Gm type. I really hate to put the 2 little letters anywhere on this site but you know what I'm saying the I live not very far from this salage yard with a bunch of these trucks so parts will not be a problem to get. heres a story for all you ford lovers I lived out in the country and about 200 yards from my neibors. This guy was a die hard chevy fan he lived and breathed chevy. One evening I was out cutting the grass and I heard his truck puttering down the road then it dies , I wait and when he could not get it back to life I decided I would jump in my 88 f150 4x4 and go down and offer him some help, after we fooled with this "crap butt truck" I said hey my chain is In my bed we'll just hook mine up and pull it up to his garage. MAN You would have thought I told him someone shot his best dog"!! he said You are not hooking that ##@@!! ford up to my chevy and pulling it anywhere. This guy is 6-6 and about 270lbs I turned and said ok not a problem, I picked my whole tool box of tools off his truck and jumped in mine and went home and laughed. The next morning the truck was in the same place but on the side of the gravel road. When I returned home from work it was in the drive with the hood off and the engine getting jearked out..heres the killer within the end of the year there set in his drive no less than a new f 150 4x4 , and I never had to here another ford joke out of his mouth even to today!!! he only said that there alot less expensive than a chevy guess I'll get what I paid for . I said no you will get a truck this time and that was it...............................................
Love the story. To the best of my knowledge you will need a different (or lengthened) driveshaft in order to swap in the C4, because the C6 (which is most likely what you have now, it has a square pan with an indented corner as compared to the C4s small square pan) is longer. I'm not sure but I think the crossmember would have to be slid forward a bit to to accomadate the c4s mount. Also if my memory serves me correctly I do believe the frame to motormount brackets are different as well, but should be easy to find.
thanks for the info we have the complete front end off the truck and getting ready to pull the 351m , yes the transmission behind the m is a c6 I would like to keep a heavy c 6 in the truck but the bellhouseing will not swap. its a tough transmission. I would go 460 but gas here is still at 2.20 a gallon and dont want it to drink more. thanks for your alls help
I think you may be right on the frame perches havi. If you did want to stick with a C6, I'm sure that you could find one fairly easily. I've had a couple of 70's Fords with 302's and C6's, but your C4 would probobly hold up fine in a 2wd.
The frame perches are the same. If you go with a c4 you will have to drill new bolt holes in the frame to slide the cross member forward. Also the slip yoke on the stock drive shaft is too large to fit in the tail shaft housing of the c4, and the c4 is about 1 1/2" shorter than a c6. I went through all this when I droped a 357W in my '77 and decided it was cheaper, easier, and quicker to just get a c6 for a small block.
Last edited by jmalecek; Dec 12, 2005 at 11:45 AM.
thank you all for your help the 351m is out and dead on the ground. to think this was the engine that was put in the truck when new it was tuff built. I will hunt down a c 6 auto for the 302 it will be much easier than comming up short on the driveshaft.
the 302 with a c6 auto is in the truck and fired up, just have to finish the rest thanks you all for your help " just to note didnt change the engine stands just the motor mounts, the c 4 came up short with the driveshaft swaped it for a c 6, and everything lined up and fit great. now I can only hope I'm not low on power with this swap, I dont know what my rear gears are. The truck pulls a 24 ft travel trailer "time will tell"
well well now the 351 modified is in the rebuild shop, it is like 2 of them 302s setting under the hood so its a take down time once again I can make it this time. also a note a 302 is not much better than the 351 modified when it comes to MPG. thats the other thing to make me want my big M back -thanks to all "A Hard LESSON LEARNED"
here is one other ? being ford man I went out and bought a 87 f150 it has the 600 6 with a 5 speed tranny. I wanted a automatic transmission, but the deal and the condition of the truck couldnt be passed up. a 80 year old man, and unable to drive the stick anymore. I have complete right arm injury with 2 surgerys and a 70% disabilty threw out my upper extreamitive...now heres the ? what would need done to the 87 to make it automatic? cost is not a issue. thanks
if you have a 4X4, you will need a trans from a 4X4. the transfer case is the same,wether you have a stick or auto. i did ther same thing with my 88 diesel when the transfer case went. i always wanted the auto anyway, so it was the perfect time to do it. total cost was rite around $2,700, with trans and t-case rebuilds and parts, including new water pump, belts and hoses, and total brake system replacement. but then i sold the 5 speed stuff for $750, so i came in with a total layout of around $1,950. took almost 6 months to finish, because i never put more than 3-4 hours a week into it.