My GM HT383 has the vortec heads, factory roller cam and 465 ft.lbs. of torque from the factory on the dyno. I put 1.6 roller rockers on it. So, you're wrong on that.sierrablue wrote: ↑Mon May 01, 2023 11:44 am Pretty sure BJ's has them, too. Accessories shouldn't be a big deal; if they're not the same, they're easy enough to swap while everything's out.
Are you still gonna be using the Qtrac? If you're going for mileage, the full time 4wd is going to put that all out the window. If you have a 700r4 behind the 360, with a part time case, I wouldn't expect a carbureted 350 to magically get better mileage. It's about the same size and will be fighting about the same drag; the only way it would really be better would be if it had some monster low end torque, which with the big cam and Vortec heads, is pretty much out the window.
Max mileage (with easy, bolt-in Jeep stuff) would be a 4.0L (built up if you want) with a 5-speed or a 4-speed auto out of an XJ or ZJ, a part time case, and locking hubs (some claim these don't help any, but they gain me about .5 mpg, which over the course of a year equates to over 40 gallons aka 2 tanks aka $150).
Why would it be "loud and unpleasant" its not locked in 4 wheel drive all the time?sierrablue wrote: ↑Mon May 01, 2023 2:03 pm Based on what I've read, it can, but it has lots of vibrations. If you put in a third u joint (can't think of the name of that rn )(double cardigan joint?) like the front has, it'll work ok. Not ideal but it'll work.
I guess you could get the 700r4 to Dana 20/Dana 18 adapter and run a Dana 18, which has the offset, but that's going to be kind of loud and unpleasant due to straight cut gears. You're probably looking at either a double cardigan or a centered rear axle, no matter what route you go.
I tend to agree with you akguy09.akguy09 wrote: ↑Tue May 02, 2023 9:31 amWhy would it be "loud and unpleasant" its not locked in 4 wheel drive all the time?sierrablue wrote: ↑Mon May 01, 2023 2:03 pm Based on what I've read, it can, but it has lots of vibrations. If you put in a third u joint (can't think of the name of that rn )(double cardigan joint?) like the front has, it'll work ok. Not ideal but it'll work.
I guess you could get the 700r4 to Dana 20/Dana 18 adapter and run a Dana 18, which has the offset, but that's going to be kind of loud and unpleasant due to straight cut gears. You're probably looking at either a double cardigan or a centered rear axle, no matter what route you go.
And its a Double Cardan joint Cardigan is the sweater Mr Rogers wore
Oooo, a big number. The Vortec heads make more ultimate torque, but WHERE do they make that torque? Based on the graphs I'm seeing, that's not until ~4k rpms. They sit at ok torque and at about 3500 it starts a gentle climb to its peak around 4k. Are you really going to be driving at 4k rpms all day long? If so, your mileage is OUT THE WINDOW. I don't doubt they make big power, but they don't make big low end power.OldFarmTruck22 wrote: ↑Tue May 02, 2023 9:22 amMy GM HT383 has the vortec heads, factory roller cam and 465 ft.lbs. of torque from the factory on the dyno. I put 1.6 roller rockers on it. So, you're wrong on that.sierrablue wrote: ↑Mon May 01, 2023 11:44 am Pretty sure BJ's has them, too. Accessories shouldn't be a big deal; if they're not the same, they're easy enough to swap while everything's out.
Are you still gonna be using the Qtrac? If you're going for mileage, the full time 4wd is going to put that all out the window. If you have a 700r4 behind the 360, with a part time case, I wouldn't expect a carbureted 350 to magically get better mileage. It's about the same size and will be fighting about the same drag; the only way it would really be better would be if it had some monster low end torque, which with the big cam and Vortec heads, is pretty much out the window.
Max mileage (with easy, bolt-in Jeep stuff) would be a 4.0L (built up if you want) with a 5-speed or a 4-speed auto out of an XJ or ZJ, a part time case, and locking hubs (some claim these don't help any, but they gain me about .5 mpg, which over the course of a year equates to over 40 gallons aka 2 tanks aka $150).
It would be loud and unpleasant because straight cut gears are noisy and not as smooth to run. This is the big advantage of the Dana 20 over the 18, according to the threads on IFSJA. Well, that and the centered rear axle.akguy09 wrote: ↑Tue May 02, 2023 9:31 amWhy would it be "loud and unpleasant" its not locked in 4 wheel drive all the time?sierrablue wrote: ↑Mon May 01, 2023 2:03 pm Based on what I've read, it can, but it has lots of vibrations. If you put in a third u joint (can't think of the name of that rn )(double cardigan joint?) like the front has, it'll work ok. Not ideal but it'll work.
I guess you could get the 700r4 to Dana 20/Dana 18 adapter and run a Dana 18, which has the offset, but that's going to be kind of loud and unpleasant due to straight cut gears. You're probably looking at either a double cardigan or a centered rear axle, no matter what route you go.
And its a Double Cardan joint Cardigan is the sweater Mr Rogers wore
But the Transfer case gears are not making whole lotta noise until the transfer case is locked in 4x4...at that point it seems irrelevantsierrablue wrote: ↑Tue May 02, 2023 4:23 pmIt would be loud and unpleasant because straight cut gears are noisy and not as smooth to run. This is the big advantage of the Dana 20 over the 18, according to the threads on IFSJA. Well, that and the centered rear axle.akguy09 wrote: ↑Tue May 02, 2023 9:31 amWhy would it be "loud and unpleasant" its not locked in 4 wheel drive all the time?sierrablue wrote: ↑Mon May 01, 2023 2:03 pm Based on what I've read, it can, but it has lots of vibrations. If you put in a third u joint (can't think of the name of that rn )(double cardigan joint?) like the front has, it'll work ok. Not ideal but it'll work.
I guess you could get the 700r4 to Dana 20/Dana 18 adapter and run a Dana 18, which has the offset, but that's going to be kind of loud and unpleasant due to straight cut gears. You're probably looking at either a double cardigan or a centered rear axle, no matter what route you go.
And its a Double Cardan joint Cardigan is the sweater Mr Rogers wore
This $^##[!_€*~!' phone! That's what I typed the first time, and it said it was wrong! *%%#]€'dh autocorrect.
I want to respond to a few people who gave input on this.sierrablue wrote: ↑Tue May 02, 2023 4:19 pmOooo, a big number. The Vortec heads make more ultimate torque, but WHERE do they make that torque? Based on the graphs I'm seeing, that's not until ~4k rpms. They sit at ok torque and at about 3500 it starts a gentle climb to its peak around 4k. Are you really going to be driving at 4k rpms all day long? If so, your mileage is OUT THE WINDOW. I don't doubt they make big power, but they don't make big low end power.OldFarmTruck22 wrote: ↑Tue May 02, 2023 9:22 amMy GM HT383 has the vortec heads, factory roller cam and 465 ft.lbs. of torque from the factory on the dyno. I put 1.6 roller rockers on it. So, you're wrong on that.sierrablue wrote: ↑Mon May 01, 2023 11:44 am Pretty sure BJ's has them, too. Accessories shouldn't be a big deal; if they're not the same, they're easy enough to swap while everything's out.
Are you still gonna be using the Qtrac? If you're going for mileage, the full time 4wd is going to put that all out the window. If you have a 700r4 behind the 360, with a part time case, I wouldn't expect a carbureted 350 to magically get better mileage. It's about the same size and will be fighting about the same drag; the only way it would really be better would be if it had some monster low end torque, which with the big cam and Vortec heads, is pretty much out the window.
Max mileage (with easy, bolt-in Jeep stuff) would be a 4.0L (built up if you want) with a 5-speed or a 4-speed auto out of an XJ or ZJ, a part time case, and locking hubs (some claim these don't help any, but they gain me about .5 mpg, which over the course of a year equates to over 40 gallons aka 2 tanks aka $150).
There's a reason that you don't really see SBC swaps in these Jeeps; just the tranny+tcase. You don't really gain anything with the SBC--it's the same or worse in every aspect except parts availability, and most parts for them aim to improve hp, not torque (and certainly not low-end). Unless you plan on launching it and want to be able to do 60-90 faster than anybody else, that's not going to be a huge help in an FSJ.
You don't have to have guess work on that measurement, you know. Measure the housing of your 700r4, and look up/ask about the length of a 241. Factor in an extra inch or two for the clock ring you have to run, and 2-3" for the AMC to SBC bellhousing adapter. Then measure from the back of the block straight back, and see where that lands in proportion to the gas tank. I doubt you'll have problems but I don't have those mods done, so I can't swear to it.