454 for 3/4 ton 4x4 suburban

[josh0325]

I've been building a 1991 Chevy Suburban for the last two years. I had a brand new 454 installed but   I recently pulled it due to a spun rod bearing.  My question is this, I have stock 781 heads, a stock quadrajet intake, stock quadrajet carb, hypereutectic .100 dome pistons, and xe262 cam.  I'm trying to help get this Suburbans off the line, and acceleration improved.  Right now, it feels underpowered from what I'm used to in a truck.  Also has th400 transmission with np205 case, and 3.73 gears front and rear, I currently run a 32" tire, but would like to run 35's later when I can afford them.  Any help or suggestions are welcomed.

[fitz]

When you say you have a stock Q jet carb and intake, what vehicle did they come stock on?

[josh0325]

They are both stock  chevy 454 items.  1978 intake and carb non emissions. Sorry I forgot to mention that the 1991 Suburban was just a rolling chassis when I started with it. Truck was bare frame, and I put the 1991 body on if, was the only solid square body Suburban I could find.  I've completely built the truck, this is my first build ever.

 

[thefarmboy21]

Are the plugs "reading" good? Have you checked compression? I'd check the timing, the carb function, valve lash and the plugs. A motor only has to have Air, Fuel, spark and compression.....something isn't right, because a 305 could pull that thing around just fine.

Brakes not dragging, or transmission slow either right?!?!

[josh0325]

Yes, the plugs were reading hot, burnt electrode.  I swapped them out for Auto life R144s.  Timing is dead on at 34 degrees all in by 2500 rpm, trans pulls fine.Hopefully when I get it back from the machine shop everything checks out fine.  I spun a rod bearing after putting about three hundred miles on a fresh rebuild.  I don't believe clearances were checked as I had the engine "professionally" built. I was just curious if there were any suggestions that might increase low to mid range torque while it was in the shop.  Im pretty sure I was spot on though with 781 heads with nothing more than a valve job, an XE262 cam, and stock non emissions intake and carburetor.  Thanks for the suggestions once again.