1991 suburban engine swap/5.3 or 6.0 BD turnkey engine/Mileage improvement

[VANMAN]

Hello all,

Great site...I bought a 1991 3/4 ton suburban/5.7/14 boltsf/10 bolt front/...I bought it as a run around 2d vehicle while I'm rebuilding my 1990 4x4 van...going completely thru the van...great axles new paint interior etc.....penthouse top already on it....But I digress......


Didn't really realize I probably bought the best year suburban out there...and do to the fact Im OCD like most of you which is evidenced by your blogs....I'm thinking about mods to the Sub....right now pretty much stock....new springs...33" tires....yeah I love the Suburban Cummins build ( I second your thoughts on vinyl floor/did the same thing/without sound deadener/probably WILL linex it) THis thing is in Great shape....thinking of putting 5.3 or 6.0 vortec in it.... anybody done this and what was your driving impressions and mileage improvements over the 5.7 TBI ?

NOTE: IF YOU BUY ONE OF THESE WITH SAGGING SPRINGS AND NO PLAY IN DRIVESHAFT/CHECK FRONT PASSENGER SIDE TRANSFER CASE FOR CRACK/EVIDENTLY COMMON IN THESE/I HAD TO PULL IT AND GET CRACK FIXED/

 

[Rot Box]

I guess what I loved so much about the 91's was them being the last of the solid axles and having TBI injection. Those newer motors make more power and usually provide better mileage, but I love the simplicity and reliability of the TBI motors and it would take a lot of convincing for me swap one out for something else (excluding diesel lol). Just my .02 Welcome to the forum :bike_rider:

 

[Rovertrader]

I've got the same truck and getting just south of 20mpg at 65mph, and around 15+/- in town, certainly npt worth the swap to me. Mine has 119k on it, see link below. Welcome aboard!!

 

[xpndbl3]

look at my thread, i'm about done with my 5.3L swap, can't wait to drive it....been a long road to this point

 

[BurbanAZ]

I guess what I loved so much about the 91's was them being the last of the solid axles and having TBI injection. Those newer motors make more power and usually provide better mileage, but I love the simplicity and reliability of the TBI motors and it would take a lot of convincing for me swap one out for something else (excluding diesel lol). Just my .02 Welcome to the forum :bike_rider:

I completely agree the TBI injection system is by far my favorite. Its simple and easy to work on and is really reliable. I love my 454tbi in my suburban i just wish it got a little better gas mileage.

 

[dieselfuel]

my 89 GMC Suburban is sitting in my driveway waiting for its 5.3L i'll be getting mine from BD turnkey engines, Bryan is a good guy to deal with, i cant wait to get this thing running.