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I'm rebuilding a 351m for my shortbox ford and want it as a daily driver but also to have decent power any suggestions on parts and mods besides turning it into a 400.
Ya got headers? if not, I would suggest a set of them. Also, is it a 4bbl? If not, swap in a 4bbl manni and throw on your prefernce of a 600. I prefer a Holley vac. sec. myself. Also, since you have the heads off, port the exhaust side out a bit. Not too much, thou. Finally, maybe someone can recommend a slightly larger cam for your build. I'm not too sure on that cam part of it.
Other than that, maybe someone else has ideas for it.
351m is a de-stroked version of the 400. The best build will include a 400 crank- flattop pistons (9:1 Compression), straight up timing and, if smog isn't an issue, the eldebrock performer intake and 4bbl carb. A near stock cam and with or without headers your driving twice the engine with gobs of low end and better gas mileage than the 351.
tons of builds listed in this forum- use the search. Also TMI has stuff and you can get stuff off ebay as well. It's not a huge cost if done right.
A lot of folk here with good info. Cost will dictake a lot- you can use badger pistons and your own heads and come out fairly cheap with a solid build or fgo with aussie heads and KB pistons from TMI and have a bit more power for even more money.
[QUOTE=roger dowty]351m is a de-stroked version of the 400. The best build will include a 400 crank- flattop pistons (9:1 Compression), straight up timing and, if smog isn't an issue, the eldebrock performer intake and 4bbl carb. A near stock cam and with or without headers your driving twice the engine with gobs of low end and better gas mileage than the 351.[QUOTE]
Personally, I wouldn't waste my time on rebuilding it back to a 351M either. But, I just answered the question as he asked.....
i'm staying away from the 400 idea only b/c it is not better on gas than a 351 my bro's 400 gets the same mileage as my tired 460 and my dads 351 is very good on gas.
well a built 400 with flat tops is gunna get better gas mileage because if the compression ratio and a 4bbl would help too but if u wanna keep what u got thats fine with me
IMO, I personally don't think it would be worth the money. Especially if you've already got the electronic setup in your rig. It's a '78 and your daily driver, right? Plus, you're basically rebuilding it stock, with the except of headers/intake?
The OEM ignition system is very good and has several advantages. Use a Motorcraft box if you can afford a new one (obviously you can if you can afford a M$D), but if you want to save $$ they can be found in salvage yards in perfect operating condition. Have any ignition module tested at a good parts store. The computerized test machines are very good. Mount the OEM box on the fender with 1/4" spacers to allow cooling air under the module.
well a built 400 with flat tops is gunna get better gas mileage because if the compression ratio and a 4bbl would help too but if u wanna keep what u got thats fine with me
what kind of mileage would i expect from an engine like that?
Although the oem ignition is sufficient, it is not designed for performance. We offer both the D.U.I. and Duraspark igntion systems. Both are custom curved for your motor. Review them at:
Definetly don't waste the money on an MSD... but the stock system is crap compared to a Mallory Unilite magnetic distributor and a Crane Fireball Hi6s CDI box. I've had several problems with MSD units in the past and I'll never buy another. I've got the setup mentioned and its way more reliable that the stock system and much better, whats better than only three wires to deal with?
I'd go with a 570CFM Holley Street Avenger carb, Edelbrock or Weiand 4bbl manifold, hog out that exhaust port and get some good headers like Hookers. There isn't anything wrong with a 351M...
The stock DSII system has the advantage of a start timing retard circuit as well as off the shelf availability of spare parts at ANY parts store. Computerized module testing is also available at most parts stores.
Use Motorcraft modules tho and remember to mount them 1/4" off the fender for cooling and extra module life.
The DUI system uses stock OEM parts but does not have the start timing retard circuit.
Because our D.U.I. distributors are calibrated on a distributor machine with a custom advance curve, there is no need for a start retard circuit. The advance curve is very smooth, allowing you to run the maximum amount of timing without making the motor hard to start(and elimating detonation).
But if you want the stock style system, we can build you a custom curved Duraspark.