Can Anybody Tell Me What The Differnece Is In Plenums. I Mean Is It Just The Upper And Lower Plenums And Which Is Better For Horsepower And $$$wise. Also What Is The Differnece Thanks

 

Also What Is The Difference In The Sizes Like The 1/2 And I Think 5/6

 

cHECK oUT tHE mOTORDYNE aND aam wEBSITES. tHEY bOTH hAVE eXCELLENT wRITEuP oN tHEIR pRODUCTS (pLENUM sPACERS iS wHAT yOU'RE tALKING aBOUT):

http://www.motordyneengineering.com/

http://www.alteredatmosphere.com/

 

If you read advertisements for plenums such as APS, APS gives you a complete rundown on faults of the OEM plenum, and improvements of the APS plenum. Give consideration that any advertisement is biased, and may not be 100 percent factual.

 

what is the difference with the termo ones and which is better 1/2 or 5/16. is the aam either

 

The AAM spacer is actually tapered. The back end is 1/4" thick, the front is 1/2" thick. The front is where you want to increase the space to help get more air to the front two cylinders.

The "isothermal" part of the Motordyne kit is an insulating gasket than goes under the lower plenum to help keep the lower and upper plenum's cooler. Cooler plenum will result in a slightly cooler air flow into the engine.