picked up a 79 bronco about 2 weeks ago to get me back n forth for a while. she aint the prettiest but she gets the job done n i love driving it. 1979 bronco custom. 33s. 351M with weiand intake and carter afb 4bbl and longtube headers. auto. 4x4. halfback buckets. power rear window still works. in floor A/C lol. newer brakes, wheel cylinders, and axle seals

not bad for $1200, but man oh man i cant believe how much of a pooch that 351M is. ive had a few 351w engines built and mostly stock that are night and day of this engine.

any quick tips for getting a lil more snap out of the M? i put fresh motorcraft copper plugs in it @ .045, new spark plug wires, cap, rotor, oil, filter, fuel filter, sea foam in fuel and oil. ordering a new coil. not sure what to do next to put a lil more pep in her step. timing? it likes to bog down n almost snuff out once in a while from a dead stop

the previous owners son drove it for a while and put new engine gaskets in it at tech school...and he also put the distributor in 180 off ugh what a nightmare to try and figure out why it wouldnt fire after the tune up. eventually got fed up n started moving all the plug wires one spot over til it ended up firing right up when the were 180 degrees off of what they were supposed to be.

 

460 swap! Hehe was this on craigslist? It looks familiar.

 

yeah it was on craigslist in mondovi wi. i have a 460 in the garage but thats for my 79 crew cab...514 or 521 stroker. i have a 351w block and a complete 302 in the garage as well but would like to just keep it in one piece for now

 

If it is wanting to "bog down" then it most likely needs some carb tuning. If the carb aint right it wont ever run worth a crap. And all the other things you do to it wont help much either.

 

But the distributor was known to be buggered on the install. Safe bet it's still off.

Get a timing light on it and see where it's at for the initial, how much mechanical and when RPM wise etc. A few degrees here and there of timing makes a big difference. 2 degrees worth of adjustment on the initial timing is about the width of a pencil line on the distributor body.

 

thanks guys. yeah ill probly spin the distributor back to where it should be n go from there. carb looks like it needs a rebuild or just throw a quick fuel slayer carb on. never been a fan of the carter/edelbrock carbs

 

broncos been gettin slowly upgraded the last couple weeks since ive owned it.
cd player installed in a box on the floor hump that the previous owner made so he didnt wreck the dash.
all lights working correctly except need license plate lights yet
new windshield wiper blades
new plugs, cap, rotor, oil n filter
finally got license plates n registration in the mail so got those put on
new mufflers
new ignition coil comes tmrw then ill throw that on.
got a new windshield seal so im just waiting for a decent day off to try my hand at installing my old windshield from my crewcab with the new seal
next up after that will probly be a new carb and get around to checking timing and gettin the distributor set in correctly.

love how fast this thing heats up n ow warm it gets inside.

 

got a chance to putz around with ol blue a lil more today.
replaced the cracked n hardened brake booster hose that goes to the carb
put 2 new tailgate cables on and straightened out one of the tailgate pins that was bent down
checked for vacuum leaks on the engine and found no leaks
checked timing and it is right around 6*-8* BTDC which sounds about right
then i messed around with the vacuum advance on the distributor which seemed like it was almost all the way out which is where its least sensitive. turned the adjuster screw in all the way and started doing some test drives until i got it adjusted to where i like it. running pretty decent now.
but i still have a backfire through the carb when im cruising and blip the throttle. pretty sure it my carb. ill be buying either a quick fuel tech slayer series 600 for it or a summit brand 600 carb as soon as i get all my xmas presents squared away.
im a little curious about the throttle linkage setup. i have to almost put my foot through the floor(which is possible haha) and hold it there before it kicks down. either something isnt hooked up right or is out of adjustment and im almost positive my secondaries arent opening up.

 

[QUOTE=HpCowboy13;15850480]got a chance to putz around with ol blue a lil more today.
replaced the cracked n hardened brake booster hose that goes to the carb
put 2 new tailgate cables on and straightened out one of the tailgate pins that was bent down
checked for vacuum leaks on the engine and found no leaks
checked timing and it is right around 6*-8* BTDC which sounds about right
then i messed around with the vacuum advance on the distributor which seemed like it was almost all the way out which is where its least sensitive. turned the adjuster screw in all the way and started doing some test drives until i got it adjusted to where i like it. running pretty decent now.
but i still have a backfire through the carb when im cruising and blip the throttle. pretty sure it my carb. ill be buying either a quick fuel tech slayer series 600 for it or a summit brand 600 carb as soon as i get all my xmas presents squared away.
im a little curious about the throttle linkage setup. i have to almost put my foot through the floor(which is possible haha) and hold it there before it kicks down. either something isnt hooked up right or is out of adjustment and im almost positive my secondaries arent opening up.[/QUOTE
A backfire, be it from the carb or the exhaust is usually gonna be timing. The backfire is caused by either the intake or exhaust valve not being completely closed. If you are backfiring through the carb and it feels doggy, that means the timing needs to be advanced; I would start there. One of the shortfalls of the 335 series Ford V8s is the factory timing set. They had a 4 degree retard built in the sprockets for emissions. Many of the aftermarket "adjustable" timing sets give you the option of -4, 0, and +4. Being the age of the truck, it's possible that engine has been rebuilt or freshened up. I wouldn't be surprised if one of those timing sets had been installed. That being said, you more than likely will not be able to set the timing to factory specs. You'll probably have to play with it a little bit before you find the sweet spot. A timing light will be helpful.

 

thanks pkupman. i have a timing light. on one of my days off ill start to mess with it n see what happens. i know the engine was removed and had new gaskets and a few other things replaced by the previous owners son at a tech school but he wasnt sure what all was done to it

 

No problem, yeah it's pretty amazing how much of a difference it makes just when these engines are properly tuned. Going to a Holley carburetor will give you a lot more tunability as well. You can make jet changes and float adjustments without removing the carburetor. It's been proven time and again you will actually get more desirable performance and power gains from a Holley. I'm not downing Edelbrock, they have their place and they put out a good product at an affordable price. I have a custom built Holley on my 79. It was done by Pro Systems (they do have a website if you want to look into it), they will set up a carburetor to run on any engine. The performance is incredible, the throttle response is crisp and snappy, you would almost think it was fuel injected.