Bought an overhaul exchange 4.3 mercruiser from US engine on line. I had some warranty issues I wanted help with from owner MR. Charlie Silvers. Most arrogant, combative, nasty human being Ive ever done business with. It took a credit card dispute just to get my core deposit back. My issues were oil consumption, Popping sound out intake at times, and Low WOT rpm. I ended up changing carb I suspected too rich and it seems popping sound is resolved. (been through timeing many times) The jury on oil consumption is still out. The WOT RPM remains. Prop cant get much smaller 14.5 X 15 on a 21 ft boat with 8.5 ft beam 1992 celebrity fishawk. Ive never seen 4400RPM this engine or previous. 4000 max. Also id like to add PCV valve But there doesn't seem to be any port on this 12 bolt intake manifold. Any one have any suggestions?