Simple TBI build

[chris989]

Hello All,

I thought i would share my new TBI build and results with the forum. I have searched a ton and finally decided to keep it simple.


I use my truck as a DD and to tow my 8500lb camper in the summer. Most builds talk about max HP/torque. My bigger concern was usable torque at 2500-3500 rpm and at <half throttle. You can't tow at WOT and 5k rpm for long. For that reason I decided to keep the swirl port heads, My thought is velocity is what i am after not big flow numbers. I fully understand the limitations of these heads but for now i wanted to be back running this spring and not get into fueling and programming issues.



I want to keep the motor around 2300 at 65 in OD and up to 3100 in third at a down shift. The idea is to keep it in the max torque range while working. For this build there is little value in numbers over 3500. I hope i will still get 15+ mpg around town and 10-12 towing. If i can't get there, i will build a BB and sell this motor at a later date. The cost of to build a 383 kept growing so this was alternative for now.

Overview is
5.7 crate GM
lunati cam
full length hedmans
4l80
small block 4l80 converter (stalls higher than the BB version)
4.56 or 4.88s

Anyhoo, Here it is,, I will post the pics and specs as it develops and a bin file for the computer at the end if needed.

This is my OEM TBI 5.7 I sold the long block for 300 on CL.





I bought a new GM crate 12568758 from summit for 1640 free shipping, no tax. (-300 for the original) new motor cost 1340. It is hard to touch that number with a local machine shop. It has hypereutectic pistons and a CR of 9.4

http://www.summitracing.com/parts/na...make/chevrolet





It is a roller block but i am staying flat tappet. I am installing a Lunati cam (113$) lift .437/.454 Duration 250/256 and using the GM lifters I was going to polish the heads a little but they look decent enough. I do not want to open them up because it is the velocity at 1/2 throttle i need. The longer duration should should help.

http://www.lunatipower.com/Product.aspx?id=1981





I know I could go roller but the point of this is to make my 7.4 vortec numbers (Vortec L29 454 290 hp 410 lb/ft torque) without a bunch of money and tuning. I doubt i will get there but that motor towed great and still got respectable mileage.



This is the truck it is going in.




If you have any input on parts,,, please advise, If you are interested in the outcome, let me know and I will continue to update.

Chris