Just picked up a 77 hiboy. Not my first one but i'm gettin back into the game. My previous trucks had either a 390 or 460,as near as I can tell this has a 351m automatic, I'm thinking it is not original, anyway it will be used to haul my 29ft camper to my spot in the MTNS in spring and bring it down in the fall. otherwise huntin' and playin' (not a daily driver) My question is should I leave the 2barrel carb or upgrade to a 4barrel. It is my understanding that the 2 has more torque. I live @ 4700Ft and travel up to 9000Ft. Any help will be appreciated.

Oh, By the way I have been reading alot of threads and this is a great site, you guys know what your talkin' bout!

 

351M was avalable starting in 77, the last year for the 360 was 76. Are you sure it's not a 400? You can't tell them apart by looking at them. If you need more power a free flowing exhaust and good induction system would be a good place to start. At 9000ft that engine is going to need to take a deep breath.

 

I'd leave the 2V on, the primaries are bigger. You may have the Motorcraft 2150 on there and it's a good carb. Fastfarmers' good idea to go with a more voluminous air induction, like a 14" round filter housing doesn't cost much, and bigger exhaust pipes. If you felt that you needed them way up there. My stock '78 400M hauled trailers across the Divide a couple of times with no problem. And lived in Flagstaff for a while.

Nice truck, and Welcome to FTE

 

ps: Here's great info on our 335 series

335 Series- 5.8/351M, 6.6/400, 351 Cleveland - Ford Truck Enthusiasts Forums

 

A 4 bbl is only good for 2 things.. saving fuel when cruising without any load and extra power when passing someone.
I suggest just keep the 2 bbl on it.

BTW, 2v carbs don't have primaries.. They are the only Venturis.

 

Hello all, new to the site and hope to do things properly.

First off I have purchased a 1977 F250 4wd with a 400 in it. Problems with it and wanting to be worry free I decided to purchase a long block from the local parts store and replace all the underhood components.

I had a friend "donate" a Edelbrock 400 Streetmaster aluminum intake. I do not have, nor do I wanna spend the money on a 4bbl carb unless it would be a definate improvement. So I guess my question is, should I just stick with the factory intake and newly rebuilt Motorcraft 2bbl or use the aluminum intake with a restrictor plate.

And can I safely run my truck without an EGR, I'm trying to do away with as much emissions control as I can

 

im running an edelbrock performer 400 manifold and a holley 670 street avenger on my truck and all i can say is the 2bbl carb sucks. HUGE HUGE HUGE power gain, and way more torque and go. and when you step on it and the trans kicks down i can spin the tires.

My fuel economy went up by atleast 2mpg and the increased power is great. I also ran a holley 600 carb and it was just as good. only reason is stepped up to the 670 street avenger was it happened to be to good of a deal to pass up.