Hey guys im new to this forum this is my first post and i need some help i am wanting to do a 12 valve swap into my 99 chevy tahoe i have the motor it is in my freightliner box truck im wondering how much power i can get out of it withought getting to much into the internals of the engine and which trans would be better the gm 4l80e or a dodge 47re or whatever the dodge auto trans is what kinda mpg would i be looking close to with different hp setups tia guys

 

This would be best put in our swap section, but here goes.

The 12 valve dressed out is roughly 1300 lbs, while it will fit, it will quickly kill your suspension. A 4BT, the 4 cylinder version is far better suited for this swap.

How much power to make simply depends on which pump you have, if it is an inline P7100 IP, you can run 3-400 Hp without spending much at all, you can go way more than that witrh a basically stock engine though.

The trans, at least in my opinion should be a 47RH ( note the 94/95 hydraulic version ) Getting a 4L80E to live will require raising the line pressures so you don't kill clutches, not to mention a chevy pattern adapter for the engine.

 

I plan on doing an sas so that is going to take care of my suspension problem and yes its the inline p7100 injector pump it is in a freightliner 18 wheeler box truck at the moment and i had a 4l80e in another truck sittin in the yard ithought about using but i may just go ahead and try to find a 47rh with a cummins plate on it i will try to figure out how to post pics of the motor from my phone if i can and post some of it

 

here is some pics of the motor, the truck its coming out of, and the tahoe i am putting it in

 

the VE pumped `92 12v with 12 qt oil, oil filter, starter, `94 adapter plate(for a 47rh trans) flex plate, Vacuum/ power steering pump, fan with fan clutch, alternator,A/C compressor, and fan belt weighed 980 Lbs on the local certified scale.I took it there on my 545 ford tractor front loader bucket and set it on the scale. I`ve seen too many internet guesses passed around as gospel as to how much a 12v Cummins engine weighs. so I WEIGHED mine. a P pumped motor should weigh about 75 Lbs more. my `92 12v with 47 Rh trans has been in my wife`s `94 1/2 ton 4x4 suburban since `08 and has about 90,000 miles. NO trouble with the factory I.F.S. every thing works for her daily driving and grand kid school buss duties. if you drive like "Bo"& luke Duke drove the General on the Dukes of Hazard, you might have front end problems. either way I think you`ll love your Cummins swap after you get it done.

 

Mine is from a 92 freightliner but it has the p7100 injector pump on it so i think it may have been swapped in to replace an older motor at some point in time but i am more than likely going to do an sas when i do my swap just cause i already have the axle but i just drive it like a truck is supposed to be driven i dont put it in mud or use it like a dune buggy or anything like that and have you got any info you could share about your swap jtamulonis

 

Have you got any pics of the swap in the suburban i could see?