Rebuild or replace my 351m?
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Rebuild or replace my 351m?
Everyone seems to dog the 351M motor. I recently ran into an issue with the dizzy not wanting to budge from my block, but since I've decided to have it tanked, I'm going to have them get it out. Should I spend the money to bore and rebuild my heads? Pricing seems better, than to buy a crate motor or something. What do you guys think? Go with a different motor, or rebuild?
Jason
Jason
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From: western montana
I would spend the $$ and build a 400 out of it...and go with 1971 spec or aftermarket. The 400 was a kickin motor but was dogged out for smog regs...then they used the 400 block and heads with a different crnk and pistons to make the 351 modified which is a step worse.
The idea is to return to the '71 400 which will amaze you. You will need a 400 crank from a boneyard and badger 400 pistons from tmi or on ebay. use the same heads but rebuilt.
use the search function for '400 build' or similar and you will find build specs for a machine shop to follow. if you get a crate 400 it will be not be built to '71 specs and you will give up performance and economy. You will be into it a bit more but the difference will make you believe again...
The idea is to return to the '71 400 which will amaze you. You will need a 400 crank from a boneyard and badger 400 pistons from tmi or on ebay. use the same heads but rebuilt.
use the search function for '400 build' or similar and you will find build specs for a machine shop to follow. if you get a crate 400 it will be not be built to '71 specs and you will give up performance and economy. You will be into it a bit more but the difference will make you believe again...
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I believe Roger is giving great advice. You should check out TMI's site for info., the man knows what he is doing when it comes to the 400. By not rebuilding as a 400, you are giving up a ton of torque, and it won't cost alot more to build. Just my opinion, though.
I'll have the Roast Duck
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From: Northshore, MN
what roger said. dizzy on my old plow truck is stuck, too, so I thought drop the pan, remove the oil pump, and tap up on the bottom of the dizzy. At the very least, replace the timing chain with a roller set straight up at zero, but it sounds to me you already have it disassembled.
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Originally Posted by havi
what roger said. dizzy on my old plow truck is stuck, too, so I thought drop the pan, remove the oil pump, and tap up on the bottom of the dizzy. At the very least, replace the timing chain with a roller set straight up at zero, but it sounds to me you already have it disassembled.
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From: Alamogordo, New Mexico
Rebuild what you got, thataway you know what your going to get. I recently had my 351m rebuilt and love it. It's stock, but purrs like a kitten and will pull down a house. The low gears help of course, but wooooooooooo doggggy, do I enjoy that motor. Prior to me busting a valve spring in it, it had a cam and the top end had been rebuilt. I ran in to the guy who owned it before me who told me he bought the cam from a local machine shop for $20.00 and had rebuilt the top end. When I pulled it apart, I found 3 or 4 other bent push rods. Long story, sorry, but I am glad I had this one rebuilt instead of buying a crate motor. It was the first time I put one back together myself, and my son and I put in back in the truck. It gets about 12 mpg, still needs a lot of work, but ain't that what it's all about?
Rich
Rich
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From: western montana
Originally Posted by 78ford351m
Yes, I have a sitting block. Do you guys think I'll have to bore it? Not sure how to tell. I am tanking this block for starters. Where can I pickup a crank and good pistons for the 400?
A lot of this adds up of course and there are trade offs. My opinion is that you should do all that you can once the motor is out as thats the hard and pain in the butt part. Especially if you plan on keeping the rig. My project has gone on far too long as I went a bit overboard but I plan on having a solid motor for some time when it's all done.
