Hi there

I have a 69 crew 4X4 with a 360 and it is gutless when ever I get on it to go up a hill it usually spits back in the carb but if I let of it runs not to bad Float problem maby????? any way a budie and i who thinks he knows everything were discussing if a lifted pickup can pull the same load as one with the factor hight. Do you guys think a lifted pickup will not pull as well? My pickup is a factory high boy with 33' tires. He seems to think that it will be useless to pull a trailer. He thinks i am nuts to have it this high.

Also, on the subject of tires, he thinks the wide ones are useless. He thinks you have to have skinny ones to get through anything. I understand that overkill will hinder it to get through anything. I was just wondering what you guys thought of all this. If you have any experience with this to please share so I can settle this dispute one way or the other

thanks for the imput

engineguy33

 

Your buddy is right in a sense, if you are running a stock 360, then it will be a bit more gutless then before, cause of the add'd weight and bigger tires, but w/ a litte motor work, it will tow just as easy as anything else. All depends on where your money goes, and as for tires, I know that skinny ones help in the snow, but in the mud, my understanding is you want wide, not too wide, to get more traction and throw the mud.

 

Final drive ratio, tire diameter, total vehicle weight, and torque will determine if it is a dog or not. Not the height of the lift or even the width of the tires. In the 4x4 forum there are many topics on wide vs. skinny.

A bad carb and bad timing will make any truck gutless. The 360 is fine for towing. After putting on the new 351W adapter/cap/rotor/8mm wires onto my 390, I am now able to run at 10 BTDC instead of 6. Little things matter.

 

Also don't forget that the larger tires will affect the rear-end ratio where-as you originially would have had a decent/low gear very capable of pulling, the larger diameter wheels and tires would change your gearing for the higher and give you less pulling power. Could always change the rear-end if need be.

-J.Banks-

 

I used to do a lot of towing with a 75 highboy, so it definitely can be done, just gotta have the gear for it. The bigger issue with lifted trucks is stability when towing. Keep in mind, the statement factory lift isn't really the case, because a lift implies modified, these were stock, and every 250 4x4made in that time had it, so they were designed to be able to tow. All you do with the bigger tires is possibly lower your max load, due to tire capability, and make the gear ratio less so it doesn't seem to have the same power.

 

Your asking a loaded question, it does sound like you are having motor troubles.

First and foremost solve your engine troubles. A 360 should not be "gutless" going uphill.

Second, after lifting install bigger tires. Did you regear to compersate for the bigger tires?

Skinny-Wide? your on your own on that question.

 

skinny vs. wide affects fuel mileage more than anything. As far as being useless for towing, I really have to disagree there. I drove from New London, CT, to western Washington in an 84 F-250 lifted 6" with a straight axle swap, 35" mud tires and a 300-6 turning a c6 auto. I was pulling a trailer, and the gross weight with fuel was almost 12,000lbs. The truck was no hotrod at that weight, but could get out of it's own way. Going through the mountains, I never dropped below 35, and at that speed I passed several trucks and a couple of rv's.
Gearing is the main factor when you modify a vehicle- that truck had 4:10 gears, so the rpm's were almost always within the engine's power band. If the tires are much larger than stock, you need to change the gearing to keep the engine happy at any given speed. With larger tires and a stock engine, it may not have the get up and go that it did with small tires, but just putting an electronic ignition, 4BBL and headers on it will give back all the power lost then some.
In the case of your truck, I would first check the timing (with vacuum advance disconnected), then rebuild the carb. It may have a bad power valve, or a piece of debris in the main jets.

 

if its popping going up a hil when you give it gas it sounds like the timing is off or your vacume advance is not working. test the diaphram to see its good and recheck your timing.

 

You can really make this truck haul a** for a few hundred bucks. If you don't already have this get it: 4bbl carb and intake, some sort of cam ie: rv, high torque, headers, new plugs and wires, points and condensor. These will really wake things up because now you are helping the engine work less hard to breath which will result in more power to the wheels and probably better mileage.

I will give you a couple of examples on lifted trucks pulling.
#1 my 1971 f-250 4x4. 390, 4spd, 410 gears,4" lift, 35x12.50 mudders, dual exhaust. I pulled a dead 71 3/4 ton 2x4 from a farm out to the junkyard and had to climb 2 very steep hills. You'd have to see them to appreciate this comment but anyways, 3/4 of the way up doing 60mp/h I started to bog down so I shifted to 3rd gear for the rest of the hill which I was revved out and still doing 45-50mp/h.
#2 A friend has a 97 Dodge 3/4 ext. cab deisel on 8" lift 38.5 boggers and only mods are bigger injectors and throttle body tinkering. He put an old(78-79) 10.5' camper on the box loaded to the hilt for 2 weeks of camping, a 18' car hauler trailer with 2 quads, a 15' boat, 20hp outboard, 5000 watt generator, 8 gerry cans of fuel plus his 345lb carcass and his girlfriend's not much smaller figure as well. He went up the highway into the mountains to camp at a glacier lake on a goat trail of a road. I was there with my 98 f-150 barely anything in it and I really had a hard time keeping up with him on the hills. He was able to pull most of the hills in 5th, and 4th gear on the really steep ones.
More torque means less work to move the weight. More height within reason won't affect towing or hauling.33" tires aren't much taller than factory originals, just wider.
BTW even as high as the camper was in the wind his truck never really leaned around corners any worse than if he was empty.

 

Thanks guys

The tires I have on there now are 285r16 and the old ones were 265r16 they are a little wider but not a whole lot they did set it a touch higher. I think the gears will be fine as it was kind of gutless before. I have a brand new 4 barrel 750 edelbrock on it but with a spacer to the original stock intake. I will check timming I did want to put the pertronics II into it I think it would help. some one mentioned the floats set to high that's why it's puffing back into the carb cause it can't burn all the fuel. I like this pickup as all my buddies can go to my old engine shows with my trailer full of engines but I want to be able to pull them with power to spare what about a differnt engine any recomendations??????

again thank everone

I would like to try and get pictures on here for you to see as this one was a mess when I got it

take care

engineguy33

 

I know guys will jump in here right quick once they get all the details on your engine.
You put a 750cfm on a stock 360 and 2bbl intake manifold adapter?? Kinda like using a bucket to pour water into a flask!! Way too big a carb for what you are running, your flooding!
Unless you are running a 390 bored over with 10.5 to 1 compression a huge cam and ported heads revving 7000rpm for racing that carb will be a headache.
If you are running stock exhaust manifolds there is another huge problem with being gutless. They were designed very poorly and cannot freely let the exhaust flow out the pipes. Way too restricting. With a carb that big sucking in air and gas it also needs to push it out at the same sort of volume. You will need to buy headers and make the exhaust a free flowing DUAL exhaust. I think you should find a 390 put a performer intake on it, a good cam, port the heads, and headers to dual exhaust. Put 360 pistons in it to up the compression to 9.5 to 1 and once it is broke in put your foot to the floor and watch those 285's melt off the back. Your set up is wrong for what you are trying to accomplish. Surf the forum in the FE series engine section and you will be blown away at what you will learn from those guys.

 

If you are planning a rebuild getting a 390 is simple. Order a 390 crank, piston rods and flat top pistons. get a 4bl intake for it and a cam designed for what you want the engine to do. A 600 cmf carb will do nicely on that motor. You have several options for hei, go with the one that you are comfortable with. Bigger wider tires will affect get up and go because they are heaver than stock. A lifter truck is just as good as a stock 2wd for towing. Wider tires increase your load range over skinnier tires. Load rating is a mathamitcal equasion determining how much weight is exerted on the road by your vehicle. The wider tire spreads the weight out over a larger area and therefor gives you a greater load rating.

 

I have plenty of experience towing with these old trucks. The FE engines have never ceased to amaze me with how much they will pull. My 70 F250 that I tow with has 35" BFG's, 4.10's, NV4500 5 speed and a mild 390. The 390 has D2 medium riser heads with some work (nothing real special), a 67 cobra jet iron intake, 901 cam, 9.5:1 comp. and is carefully assembled and tuned. The truck sits at 7500 lbs usually, as it's never really empty and it's got plenty of go power. I've pulled a 17,500 lb trailer (25,000+ gvw) over the steepest pass around in 4th gear, 65 mph, 2550 rpm. I maxed her out with a 24,000 lb load of screw machines. 4 times the max gvw of the truck was a little rough on her. I was in third a few times on the little hills on I-5.

As for narrow vs wide My 70 originally had 34X6.50X17 bias plys on it and did very, very well off road. They were a not too aggressive retread. They sunk in mud, but did amazingly well in the snow.

Dustin

 

Are you sure they were 17's, not sure about that, never seen original 17's on these old trucks but there's no telling what can be done

 

What you need to do is find the stock tire size, particularly the diameter and use that to calculate the circumfrence of the original tires when the truck was new and compare that to the circumfrence of the new tire. Multiply that ratio by your final drive ratio to get your new final drive ratio adjusted for tire size. It's kind of difficult to explain in writing, but if you find out the diameter of the tires that the truck originally had and send it to me, I can calculate it for you and give you some idea of the new final drive ratio you want.

Greg