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currently my 715 has the stock 230 tornado. Im looking to do an engine swap when i get home from deployment in the summer. I was thinking of a 350 or a 454. just wanted to get some ideas as to which one would be the better choice, or any other ideas yall might have. not looking to throw down the $$ for a diesel. Thanks
I'm in the same situation as you .you will get more info if you use the search option as most most of the swaps that are used are not direct and will take some fabrication. depending on your skills set there are many configurations that can be used to repower our trucks. lots of luck, good hunting, and thank you for your service.
Well if you dont want to plunk down the dough for a diesel then you might want to consider the small block. Parts for a big block are always more than a small block both new and used. Small block chevy parts are everywhere and cheap. I would hazard to say the cheapest of any make--chevy ford or dodge.
That said if I had to do it all over I would have just waited until I found a 6.5 diesel and just done it. There are alot of surplus trucks/blazers with the 6.5 automatic trans and mated transfer case out there. I got a great deal on my engine out of a wrecked camaro and I'm way too far in to it to turn back now.
Just something to think on
thanks for that. im not in any hurry to do it, so maybe i will hold out.
I did a 396 Chevy Big Block, fuel injected it, and currently run a TH400 behind it. It is a good runner, and plenty of power, but I am planning to go diesel soon. Why? The big block is noisy, hot, and gets around 5 MPG on a good day, unloaded, mostly downhill.
A diesel on the other hand will have as much if not more torque, get double the mileage, and run cooler, and won't need to work as hard doing the job.
That of course is my personal preference. Individual results may vary......
I think diesel are better in our kind of truck because they offer more torque at lower rpm ..... that give them a plus with the weight of those trucks
if you do your homework and look a little bit, you will see that diesel engines can be had for about the same as a gas engine. I see 6bt cummins all the time for 1k-1500 dollars with decent miles. they are cheap to rebuild and last forever. by the time you buy a decent 350, do any work to it at all you will have that much tied up in one. Go diesel you won't be sorry.
Plus they just peg the cool factor--nothing better than belchin back coal
snakeeater, where are you seeing these prices? sounds like im going diesel too. but i dont know anything about them is the problem
Patience is the key. The first generation 6B motors with the VE rotary pumps (used on Dodge trucks up to 1993) are the cheapest. The non intercooled versions of these are even cheaper. They are still rated at 160 HP and 400 TQ which is still plenty.
The second generation p7100 inline pump motors bring more but can be had. I saw a motor with a buy it now for 1400 on Ebay that was local to me. Great deal. These are easier to get insane power out of and are still mechanical.
The later second generation (model year for Dodge) 1998.5 is when the 24 valve came in. These can still be had at a descent price. But you have wiring and an inection pump that was prone to fail with low fuel pressure. These motors had lift pumps going out as soon as 150,000 miles and killing the pump. They are good motors, just take more $$$ and time to make them on par with the 12 valve version.
Weight is certainly something to factor in. The 6B dressed out is almost 1200 pounds! That is a lot of weight on a drive axle.....expecially if it is not built for that. The 715 Dana 60 ( IN MY OPINION) will survive street driving, but with repeated loads or in a bind, it will break. These motors come opn string real low
All I can speak of is on the Cummins because thats all I know/deal with.
What I'm thinking about: Is there any chance do deal with Jeep Diesels 2.8 or 3.0? The 2.8 has a nice TQ, but only 177HP. Could be bolted to a NSG370 6-speed, like it is done in modern Jeeps, so with 4.56 Gear there must be a wide range of choices for the right Power or TQ. What's about the TC (NP200 is divorced, so it might possible...?)
The 3.0 is married to Auto TM, NSG don't like much TQ...
Never noticed about a built with one of those engines. Why, to expensive?
I agree a Cummins would be a great swap especially an earlier 12 valve but some of these older small blocks can be had for cheap. I have a 350 that threw a rod this fall on a trip and whats nice is since I already run a SM465 my chevy engine options are plentiful. I recently got a FREE '74 suburban with a running 454 and a bad tranny that I'm going to swapping in over the next few months.
Also remember that a 6BT Cummins weighs 1100 lbs and generally runs at low RPM (Think my Dodge 24 valve redlines at like 3200, and peak torque is at like 1700-1800 RPM) so your stock axles would probably be too deep of gearing. If you catch the diesel bug like I have your Cummins will be putting out serious power and you'll likely have axle survival problems. Also I think 1991.5 and up engines are intercooled so you'll need to figure that into the front clip area as well.
At the end of the day it depends what you’re doing with your truck. Lots of highway? Towing? Occasional trail riding? My truck gets terrible mileage but I don't care since I only use it on 4x4 trips where I tow it out there. I get 11-12 mpg towing it with my Dodge Cummins, probably double what I would get in the Jeep.
those 1100 pounds certainly is an issue, i plan on mine being a mostly light to medium offroad (nothing too crazy) vehicle and and beach truck (once i get EVERYTHING painted). what are some peoples mileage like with a 350 pushing around 300 hp and 350 or so tq? one of my buddies says his is decent but he also isnt pushing around a 5/4 ton truck
With a small-block Chevy, stock gearing and transmission, you can expect around 4-5 MPG........
My sbc with stock gearing and a th400 gets about 10 mpg highway.
the Jeep 2.8 or 3.0 diesels could work but the nsg370 is probably a little light for a 5/4 ton truck. None built with these engines because they aren't available in the US and would be expensive relative to cummins 4bt or 6bt.
i am going to go with 350 tuned port injection set up . i have a 350 out of a 89 iroc camaro and all of the other parts to go with it ( bought the whole car ). the 87 88 89 have a roller cam and liftres and a mass air sensor . go with a mass air sensor system because if you go with any performace upgrades the engine will make more horse power but if you go with the map sensor system ,and if you made any upgrades you have to reprogram the mem cal in the computer . the tpi makes good low end torque and the engine was getting well over 20 mpg's in the camaro . also the nice shinny tpi runners looks nice under the hood . but if you go this way buy a whole car because buying parts here and there will cost way more . chevy stuff is cheap and plentiful . it doesnt take much to make 300 hp and 400 ft torque .
With the OD trans and taller tires it should get good mileage even with stock gears, too. There was someone on here a while back with a similar setup who claimed over 20, but he had modern axles with gears in the mid 4's on 40 inch'ish tires, too if I remember right.
That will be the key.Quote:
Originally Posted by 2ndA
With stock gearing and transmission, the fuel mileage is pretty abysmal. Usually around 3,200 RPM to run 55 MPH with a small-block and stock drivetrain.
I'm almost pulling this from thin air, but if I remember right a 350 with a 700, tires around 40 inch and gears in the mid 4's turned 1700RPM at 55, and with the stock gears 2000 or 2200. Vast improvement over the stock trans and tire diameter no matter what.
anybody else heard about this?
You can download this spreadsheet and put in any numbers you want and it will tell you the rpms at certain speeds...
http://www.m715zone.com/jonmisc/RPM_Calc.xls
Running a true 40 inch tire with 4.56 gears and a 700r4 trans with a top gear of .7:1:
55 mph=1475
60mph=1609
70mph=1877
A bit low I think...
FYI: A 1:1 top gear and the 40 inch tires and 4.56 gears yields 2299 rpm at 60 mph...
WOW, now that what im talking about. thankyou thankyou thankyou
The cell I11 in the spreadsheet seems to be wrong, but no consequences. Must be 5 (mph).
Nice sheet for planning!
Found the error, fixed it, uploaded the new sheet...so delete what you have and download it again and you should be good to go.
Thanks for pointing that out so it could be corrected!
very useful, thanks again
We're working on a 4bt with the ZF 5-speed set-up to swap in this summer, we did the 6.2 diesel swap and that worked out well, those motors are cheap and if they run good their not a bad choice. I like the 6.2 alot better over the 350 I had in there before the swap.
Well when I got my M715 over 10 years ago the city modifed a Ford 351 windsor motor that ran terrible and constantly over-heated. I had an old vortec v-6 that i just finished rebuilding and thought i would try that out as i dont plan to do too much more off-roading and will see if it can push it down the highway. I'll let you know how it turns out in a month or so.
I am putting together my M715 with the drivetrain from a 90 dodge, 1st gen diesel. This engine was de-tuned for the pickup, but it is easy and inexpensive to get way more than adequate power out of. I changed the exhaust manifold and turbo, which nearly eliminated the turbo lag, bumped up the injector pump. It has way more power than I will probably ever even WANT to use. And with the gearing and 40" tires, fuel economy should be around 20. . .The thing with the early dodges is that the engine is far superior to the body, so finding one with a good engine and a destroyed body, should not be really hard. I would plan on some wide tires for running beaches with that heavy of a motor, though, ..you will need a lot of flotation, .this is one place where the lighter v-8 diesels (or even SBC) might be a better choice. I don't run my truck on the beaches, . .that is what the CJ is for. . .Of course CA beaches are a lot different than east coast beaches