351M/400 Tips and Tricks

[BigBlue79]

So you've got a 351M/400 in your truck, these were found in 1977-1982 Ford Bronco's and the F-Series. These were pre-emissions smog engines, so basically they were Generation 1 of your smog. The first thing that can be done for the budget minded person is a timing gear and chain swap, what it entails is buying a 351c timing set(less than $25 for LLT Cloyes) and installing this set either(your choice) 2* degrees advanced, or straight up, now keep in mind this is for a stock engine with NO aftermaket cam. You will notice a power improvement, next I see guys replacing their stock 2bbl intake and carburetor with a 4bbl and NOT doing anything to the heads, just because it runs doesn't mean it's at it's peak, I've stalled one more with a 4bbl on it than a 2bbl, engine's are like air compressor's, make it breathe in it's gotta breathe out, so atleast port the heads, have the emissions hump in the head ground down, clean up your pushrods and rockers and check the valve springs and valve's while it's off. After you've done these(budget mindedly) then you can slap on a 4bbl and some headers, I believe Heddman are the best for Bronco's BUT you must remember, longtube headers will put the collector's right at the front of the crossmember, I DO NOT recommend running the pipes under the crossmember, that's asking for a world of problems. You probably have to make an angled turn-up to get over the crossmember then run it back. If anyone has anymore feel free to add.

[Ridgerunner]

Excellent write up.

[JSoko]

good going Blue on a side note if you can keep your foot out of it a 4bbl will give you better MPG than a 2bbl point being most 2bbls are about 550 CFM as compared to the primarys on a 4bbl at 350-400 CFM but that all goes out the window when the secondaries kick in; need a little more speed suck a little more gas