The Gen V PWM (pulse width modulated) fuel delivery system is completely different than what most mechanics, hot rodders and gearheads are used to. It may seem complicated, but you just need the right parts and it works well.Gen V engines include the LT1, LT4 car engines and the L83 and L86 truck engines. Here’s a complete description from Hot Rod Magazine.
More and more L83/L86 truck engines are available now from wrecking yards at reasonable prices, some including the 6 speed 6L80E transmission. These are great solutions for drive-train swaps because they are plentiful, powerful, priced far less than the LS3 and Gen V LT1 takeouts and come complete with everything you need. ICT Billet has just released brackets that allow you to easily add hydraulic power steering to these engines. Reference my installation guide for vendors who provide reflashed ECUs.
Here’s the latest build from John Gamache’s GTO.
When I was making up my collector flange for the exhaust system, we designed a template that acted as both the design for the gasket and the flange itself. I searched high and low, but was unable to find anything available off the shelf other than direct from GM, this is a unique flange/bolt arrangement that appears to be only used on the GEN V engine. GM wants $57.00 for a gasket and almost $600 for each downpipe that connects to the header, so here’s a simple solution.
This is the header system that the template will fit, click on the image for a higher resolution view.
Collector template -download this PDF file for fabrication.
This template is scanned full size on a regular sheet of paper so when you print it out, please print actual size so the image doesn’t get distorted. The actual diagonal distance between bolt holes is about 3 7/8″. The pipe diameter is 2 1/2″, but we elected to design the flange so the exhaust tubing entered into the hole rather than be welded on the outside, for thickness we used 5/16″ thick steel. It’s your choice, but adjust the diameter of the exhaust hole based upon the size of the exhaust tubing your’e using.
For the gasket we used aluminum and heat tempered it so it was pliable, worked great and saved a ton of money.