Which engone swap to do??

The biggest thing I really haul is vehicles on a 16' trailer. I really want the diesel for the mileage and the ability to make great power at the same time. The big block is just a lumbering giant that takes heads and a lot of money to get decent power on a tbi engine anyway and than your getting no mileage at all.
Yes you can put the turbo 400 behind the cummins. There's a company that makes an adapter plate with an intermediate shaft to make it work but it's not cheap.

Wow you are right. 11-1200 bucks, oh well.

Something wrong with your 454. Just sayin'. Low fuel pressure, timing off, something. Even my completely ragged-out '98 crew with the steel 19.5's which are 500 lbs+ of tire/wheel out back to turn over, would freaking leap when you mashed the pedal.

Yes, diesel in general is more power and mpg, but if your Vortec 7.4 is as miserable as you say, it's not running correctly.

Richard

Its been that way since day one as well as my dads 99, both were bought brand new. It never seemed that bad until I got my duramax.

Well sure, the Duramax has it whupped all the way around (except repair/maintenance costs.)

You really should look into it though. Some of that may be (really guessing here) that GM got more torque-management happy over the years with the programming, and a good tune might really wake your trucks up. Of course like I said though being sure everything else is in top shape first would be important.

My experience with Vortec 7.4's has always been in really heavy trucks with tons of miles on the engines, and I was pretty impressed with their performance. That '98 crew also had the weight of a Sneeker wrecker unit mounted to it and that's heavier than shit. The other Vortec 7.4 I had was the '96 model I swapped into my '94 3500HD that was also a wrecker, that truck scaled just under 10K lbs and it would pull a freaking house down. Another was a '98 3500HD that was a 7.4 from the factory, and I think that version has slightly lower HP/tq numbers because it's in the heavier truck - they were a little more conservative with the setup on them. I could be wrong though and that may only apply to true medium duty (above 15K GVWR) trucks.

The '98 crew had those steel Frito 19.5's, 4.10's, 4L80E, Sneeker wrecker unit, and a bazillion miles - oh, and that freakin' Ranch Hand heavy SOB -


The '94 3500HD with the '96 7.4 transplant, Dynamic self-loader wrecker unit, steel factory 19.5's of course, 4.63's and a 5 speed -


Then the old '98 3500HD company truck, 7.4, 4L80E, Vulcan Intruder wrecker, 200K miles of "not my truck" on it, sumbitch burned a quart of oil every 100 miles - this truck also scales around 10K lbs


Richard

If my 454 was a vortec I might be a little more excited to keep it. Mine is a low performance, tbi, with terribly restrictive heads, and no hopes for any real performance unless I ditch the tbi unit and start from the heads up. After that my mpg will be just a horrid. The 454 can be a good engine in the right truck with the right setup. It's just not worth putting more money in it ,for what I'm after. With gas prices on the rise these thing are quickly becoming a curse that very few people want also. Kinda sad really.

Sorry man didn't mean to sidetrack so much from your engine question, just responding to krewzlo in hopes he might take another look at the crummy power his Vortec 7.4's seem to be making.

Richard

No worries man. I actually kinda like the discussions some of these threads start. Sometimes they go a little to far, but this one has been good. I started a thread on another forum about if a small block or big block was better for heavy trucks and that thread got way out of hand. People ended up calling names and getting rude, it went on for about 20 pages lol.

I hear ya- my 454 tbi gets 9 mpg no matter what. No OD can't help.LOL For the light duty my truck sees- i have a built 700r4 that I am itching to try out in it. if that don't help(I doubt it will) I am thinking carbed LS. I'd love to go EFI LS but I am terrified of the wiring.LOL

See my first post....cummins power....im still riding on the same tank of diesel i was when i posted that last week....

And Leedog a stand alone wiring harness is super easy to hook up....i have a current performance harness in my dually and its literally direct plug in and you have a 12 volt keyed source and fuel pump hookup and its done....when your done hookin it up have a tuner turn off the antitheft and your ready to roll