Hoping the mods will let this live thread long enough to get some needed info . Hey gang. I have the fc insured and registered but I don't drive it as much as I would like because it over heats and it doesn't run as well as I want it to. It has a 250/th350 combo but it won't get put of its own way.. The 250 may need a new carb,plugs,timing,wires etc but I've been lazy about messing with it because i lack the knowledge and patience to mess with it and the location in the cab is nothing fun to mess with so I thought about just swapping the straight 6 for a v6 and hoping that I can get more power out of it. I picked up an 88 4.3 for 50 bucks last night, but it needs a cleaning,and basically everything to do a carb swap. I found a 2.8 far away that has everything I need but idk if everything will swap over I don't know enough about those v6s.. The 2.8 has been rebuilt supposedly so i may just swap it directly over. I want to build a test stand and find someone to help me tune it before I swap it so I'm not trying to tune in from inside the cab.. Thanks for the advice in advance. And I'll drop a couple of pics cuz it didn't happen with out them. Happy holidays everyone
2.8 and 4.3 are vastly different. Transmission bell housing is also different.Your cheapest option for carb parts is going to be a marine manifold. I think ‘88-‘93? Intakes fit. 4.3L changed more than a few times over the year’s
Simplest thing would be to get the 6 running better. Anybody local that could help you with that? I can't imagine an engine swap would be easy on that
What rear end do you have in it, what ratio? A healthy 250 should move it along nicely. A 1966-1970 250 is rated at 155 hp @ 4200 rpm & 235 lb⋅ft @ 1600 rpm. A 1986–1990 4.3 is rated at 140 hp @ 4000 rpm & 225 lb⋅ft @ 2000 rpm. So you would have actually be downgrading instead of upgrading with the 4.3 , not to speak of the pathetic 2.8.
Once you put a carb and some marine stuff on a 4.3L they are rated 180-200hp Straight 6 will always have more torque at a lower rpm
My neighborhood has several auto repair shops where everyone with 'out of warranty' daily drivers get our cars serviced. They always have old cars in their parking lot. Find one, talk to the mechanic and see if he can service your 250 Chevy six. It should not be difficult to get the tune up you need to make driving that Jeep really fun. You've already specified the items that you think it needs. Getting help should not be difficult.
Thank you,I dug into the net and yes they're different. Thanks I'm going to ask around...I rather do a frame swap than get frustrated when I can't figure out why it doesn't run right. I was thinking of an sbc also...i dont want to go fast i just want to be able to pull into my driveway with out too much problems.. thank you thank you for the information. i love straight 6s but they dont love me back. I'm going to talk to the shop up the street they only have old cars there. Thanks
While the bed/tools and the wheels/tires aren't doing you any favors, it should be able to move around. I'd strongly consider doing a full inspection/tuneup on the st. six first. Also check the cooling system fully. If you can't be bothered to work on the current engine, what are the chances of completing an engine swap? I've always been of the mind that if I was going to go through the effort of swapping, it's gotta be worth the effort. I wouldn't do engine, trans, driveshaft, cooling just to end up with roughly the same HP. It's gotta be worth the effort. No info here, but lots of parts. Maybe send them an email? https://www.novak-adapt.com/knowledge/engines/swap-guides/chevy-buick-gm/fc-trucks-swap.html https://engineswapdepot.com/?p=68830 https://www.4btswaps.com/threads/4bt-in-a-cabover-jeep.6138/
Apparently the older gentleman I bought this from installed a 3.50 9".. Is that why it feels sluggish on first? BTW I installed new spark plugs and it's running a lot better.
Wow! Yeah that explains why it feels sluggish. They had 5.38 gears stock so it's gonna struggle with 3.50 gears and those tall tires.
With the Turbo 350 transmission, the 3:50 rear gear should be quite a nice driver. Keep working on your tune. Spark plug wires?
Just replaced the plugs it made a world of difference.. Wires next..they didn't have them over the counter... I was going to do an oil change but ran over the oil jug...pretty pissd off at myself
I'd suggest some carburetor spray cleaner. Spray down carb throat while engine is running. With engine off, clean up outside of carb.
I did spray carb cleaner inside the carb but was afraid it was going to backfire...good to know I was in the right direction... Thanks...a new carb wouldn't hurt.
1961 Jeep FC Truck Hello, Having our drag racing scene coming to a close, we had driven some mighty slow cars, from a 4 cylinder Model A coupe, a Flathead 40 Ford sedan delivery, and a 4 cylinder Chevy Nova. Those cars had their up and mostly downs. But, the Model A got sold, my flathead sedan delivery was slow, but it lasted 5 years of numerous surfing adventures up and down the So Cal coastline. The Chevy Nova was a friend’s car and when we wanted a “no rush cruise” to various teenage hangouts, we took the 4 cylinder hardtop. If you stepped on the gas pedal, the car had a droning coming from the exhaust and we were slowly moving ahead. The fun part of being in this car was when it was challenged to the Cherry Avenue Drags against a 6 cylinder 53 Chevy Bel Air. This was the king of the “slow car division” of the teenage cars in our group. So, compared to the 58 Impala or the 40 Willys Coupe, those were snail racers…ha! When my brother was in his final recovery stage of healing from the drag racing accident, he decided to return to surfing. But, in our travels, we were limited when exploring those long, winding dirt roads in any location, especially in Baja, Mexico. There were only a few folks that had 4x4 trucks/campers that took advantage of the traction power. Discovery of surf spots after spending long winding bumpy roads was worth it, but only if one could actually get there without destroying the surf wagons and vans. The dirt roads from the highways to the actual coves or beaches were always “rough.” So, his bright idea was to get a Jeep FC100 truck. The one he found was old, dirty and needed some love. Luckily it had a camper shell on the back. We used the local power wash place to spray off every inch of the truck camper. When we got home, the camper was taken off, opened up and air dried. The truck was a nice dark green color, the start of camouflaged paint if needed. My brother had just been a part of a wild camouflaged hand painted Plymouth Coupe for our camp Pendleton jungle forays and we were old hands at the paint scheme. This truck was already a green, so if we decided to paint our additional colors, we were one step ahead of the process. Then my brother decided that a 4x4 was the answer to “all things getting stuck.” The 4x4 would have the ability to not worry about small streams crossing a dirt path to the ocean, getting stuck in high tide flat parking spots near the surf, and finally, being able to pull itself out of any rut or drainage channel by the side of the road. So, he bought a funky Jeep FC pickup truck with a homemade aluminum shell on the back. “1957-65 Jeep FC Forward Control: Tough, dependable, handles any terrain, and looks like a kookie Soviet missile hauler… what is not to love?” Jnaki The Jeep FC was unique to say the least. No one had one, as other 4x4 vehicles were definitely more popular. So, for the next several months we trudged along with the hopes for inclement weather to try out the cool 4x4 drive train. Speed was not in the cards for this under powered 4x4 truck. It wasn’t the construction of the Jeep FC, as it was built like a brick. But, it was the noise, the slow power on the grades and just an overall “not so fast” attitude during the flat land highway road trips. There was a time when we could have walked faster than driving this 4x4 Jeep. It was not the most enjoyable drives that we had taken, ever. Plus, it was the turtle speeds, we experienced, that drove us a little batty. At least, when going by a surf spot, we could actually see the whole beach at the speed we were going. But, in order to make it seem like it can go faster, we talked about painting some fast-looking scallops on the sides. At least it would look fast, despite the lack or real power or speed. We all laughed at the idea. We even got kicked off of the 101 Freeway near the Oxnard/Camarillo city, via the Conejo Pass climb before it got too steep. With 4 people and 4 longboards, the overall weight was just not enough to make it up the steep grade in any gear. When we got stopped, it was in 1st gear, on the 101 Freeway! The local CHP gave us a warning that there is a minimum speed as well as a maximum speed. Minimum being not causing traffic to back up in the slow lane. Well, it was 10-15 mph at the least steep grade and in first gear. So, the flat, coastal highway PCH, was our only means of travel. The CHP officer did not give us a ticket, but told us in so many words, go to the Coast Highway for the trip home. Not just a plodding, slow, uncomfortable ride, but with the addition of 3-5 longboards, each weighing 45-50 pounds, that was an additional weight we did not need. Although, it was a necessity on our road trips. Flames come from all different kinds of sources… some even starting from scallops... So, we did some narrow tape scallops on the side. But, that looked, not so good. With everything my brother put on the Jeep, it was the worst handling/driving, Jeep for us. One small bump and the steering shimmied like no other. (We had to stop to make it not shake, even on the neighborhood streets.) Slow, plodding and now the shimmy shake action was pushing us to the end... My brother finally got tired of being in the slow lane and having no power to climb hills and slopes, let alone, the long road trips to Baja, Mexico. So, he sold it to a local, older camper guy. In later surf explorations up the So Cal coastline, we saw it several times along the Malibu to Oxnard coastal road trips. It was parked in the ever popular beach/sand front lot campground, for several nights stay on the beach. It had to be good for something… Note: The new FC owner told us of how he was going to use the green truck. So, speed was not in the cards, anyway. Some of these beach camper folks start off at one sandy beachfront location for the 7 days pass. Then they leave for a day and come back to stay for another series of 7 days and so on to eternity… The Jeep had the room and it was just up the road from another camp site to trade off the almost permanent stay along the coastal spot. So, after my brother sold it, we picked up this sedan delivery, but now, we were limited to two longboards to carry. No racks as the sedan delivery did not have rear ones and long ropes strapped down tight still allowed sliding going around curves. Using, front door racks only were too short for the longboards, too. Our trips now had more power, but still had limited driving going up steep slopes with the flathead power. Downshifting allowed us to keep moving with the flow of traffic, sort of, but also made us shift to 1st gear when the slopes were too steep or too much traffic in the lanes. We never took the steep Conejo/Oxnard/Camarillo climb in the Flathead sedan delivery. It was always the flat coastal route, all the way back to the Westside of Long Beach. YRMV But, here is similar solution for the low powered FC. a Corvette v8 powered Jeep FC…at least it is a shade of green…
I wouldn't worry about the gearing, it should move around just fine.(My f250 has 3.54 gears/six and has plenty of power) Give it a tune up and check the timing. Does it have points ignition or HEI? Maybe swap in a new fuel filter if it has one
I will have the shop check the timing....it's running great and it's not overheating but when I'm going uphill on a very slight upgrade,it's a dog
Instead of look at this, look at that, get it fully inspected and tuned. Fluids, filters, compression, leak down, all ignition parts, everything adjusted. You already saw that the plugs made a big difference, it's been neglected. Treat it right.
With 3.50 gears and 30" tires you will be running 2150rpm at 55mph. If you change to 4.11 gears you would be at 2530rpm driving 55mph. With 4.56 gears that would be 2810rpm. Changing to 4.11 gears would probably be enough to make a differece in pulling power but you would still be able to drive it on the highway.
Ever think about a 4bt Cummins swap . It will out perform any 3.9 gas engine , available to you . 3.50 gearing and OD trans will be perfect , and fun factor will be over the top .
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