I am an new member and I am trying to decide which engine to install in a 1988 3/4 ton 4x4 suburban that I have owned for 15 years. I had decided to us the L31Hd create engine from GM Performance http://www.jegs.com/i/Chevrolet-Perf...30283/10002/-1 but after reading on here I found some issues that I am not sure I want to tackle. (1) I was planning on using a carb intake and a tbi adaptor plate after reading this great response to a simple wtb ad I am concerned with the cooling issues http://www.gearhead-efi.com/Fuel-Inj...ntake-Manifold any further feedback is appreciated. (2) although I have not pulled my computer yet I assume it is a 7747 and everything I have read says 7427 is far superior. Also I found a post by dave w ("The 93 ~ 95 TBI computer with Red / Blue connectors is 8192 Baud / 64K PROM. The early TBI computer is 160 Baud / 4K PROM. The 93 ~ 95 TBI computer with Red / Blue connectors is about 51.2 times faster and the PROM has 16 times more memory. Don't tell anyone about the Red / Blue TBI computer, prices might increase. The Red / Blue TBI computer is the secret to an AWESOME TBI system" ) I assume this is a 7427 is that correct? Switching ecms either repin or adaptor is a lot to swallow for a tuning novice. My question is can the 7747 be tuned to operate the vortec motor with the tbi until I gather the courage to tackle the swap. (3)The suburban has a 700r4 and 410 gears do you think the vortec L31 is worth the extra effort and dollars for the increased HP and torque (which I have gotten several answer to exactly what those numbers are!) verses a properly tuned engine that came in the truck stock. http://www.jegs.com/i/Chevrolet-Perf...68758/10002/-1 I planning on doing fuel pump upgrade, crossover pipe, headers and O2 either wide band or heated (we will save that for a later debate) Thanks for your time and patients Jim