Originally Posted by jugerknot
just a quick question what about the 09 4.0 sohc models will the 4.6 or 5.0 tb swap or not just wondering because i may have a doner for this crazy idea that i have.
Welcome to the forum
You should start your own thread just so you get more readers of it.
Buy a vacuum gauge and some vacuum hose.
Connect hose to intake vacuum port, may need a "T" to get the extra port
Run the vacuum hose into the cab, E-brake cable opening usually has enough room
Put vacuum gauge where you can easily see it while driving.
Drive somewhere where you can get maximum speed without getting a ticket, lol.
Drive truck up to speed and watch vacuum gauge at WOT(wide open throttle) for 30second to a minute, you want to be cruising at WOT.
You should see under 2" of vacuum at this time.
1" to 1.5" is great, but under 2" is OK on most engines
This means there is no air restriction on the intake system.
If you get below 1" then you could have exhaust restriction
Intake vacuum is what keeps air/fuel mix flowing into the cylinders when intake valve opens, if exhaust is restricted then there will be pressure in the cylinder when intake valve opens so little or no new air/fuel can flow into cylinder and you "top out" on power.
So low vacuum at WOT under load is good, but too low is not good
Vacuum gauges are cheap, $20, and a great tool to have to diagnose engine problems.
Engines are self powered air pumps, so a pressure gauge can tell you ALOT about engine/pump condition