Would I be better off putting a stock exhaust manifold back on the truck for low end grunt?
Hey Grimmjow...
Swapping back to the factory exhaust manifold will most likely increase low end torque from 1000 to 2600 RPMs. Will you notice a difference?... probably – if your engine in well tuned.
The Hedman header is a 4 in 1, and that design is known to help with the higher RPM range. The Doug Thorley Tri-Y is known for keeping lower RPM torque. I think 2.25” exhaust with a header for stock 22RE may be a tad too large… I’m sure there are those who will argue that.
Since you don’t like your glass pack, you might try installing a new cat and stock style muffler before swapping back to the factory exhaust manifold. If it is easier to swap in the factory manifold, try that.
The other thing you could do to get “a little” more low end torque is simply make sure your valve adjustment is to factory spec .008/.012”. If you tighten the valve lash, it will usually increase high RPM HP, but lowers the lower RPM torque numbers.
