Found a local shop here in Vegas to do my cylinder heads, port and polish with valve job and all new springs n parts from Modular head shop. What type of power gains would you guys expect? I want to do this since there are 0 aftermarket heads sold for the 6.8, also thinking about Comp cam regrinds while it's apart. After talking to quite a few shops nobody will make/regrind the cams except Comp. Kinda wish their was a avenue to buy new ones in a stage two but can't find any.

Can anything be done to the stock intake manifold? I have a lower metal one off a 99" van in hopes that there is a chance lol. How cool would a sheet metal one be?

Alex

 

You can have the head shop put in oversized valves.
I think 1 or 2 mm oversized can be done.

The intake is designed for torque I belive not necessarily high rpm hp.

If your goal is hp at 4200 to 5200 rpm than larger fuel pump and injectors will be needed.

If your goal is more torque from 2500 to 3200 rpm than increase compression ratio a point or two and grind cam accordingly along with head work.

Get a aftermarket torque converter that complements the goals you have.

MY OPINION!!!
The intake gets hot and heats incoming air 50 or more degrees above ambiant. Find a way to cool intake charge and you will pick up alot of ponies....

​​​​​​I think Ford changed to a plastic lower intake to help with intake heat soak. An all plastic intake would help with heat the most. I would not add an aluminum lower unless your going to supercharge in future.

A hot day 85 degrees and above will see intake temps of 135 or more. PCM starts retarding above 120 degrees I think. Find a way to keep intake temps below 120 and you will be suprised at your power.

The IAT sensor is in the MAF, so the pcm adds tempature to the reading to compensate for air reading at maf. Its best to use a lightning IAT sensor drilled and tapped into intake runner. Than reprogram pcm to not add temp to reading.