Alright I'm going to try and remember all of this. I started with my 94yj 2.5 which had a huge blow-by problem. First was complete tear down.
I started with the block. The block was bored 60 0ver. Any machine shop can do this. Next the deck was shaved to increase the compression ratio. This is a variable depending on how high you want the compression to be and what you want this motor to do. Mine is 10.5-1 and it needs high octane and gas milage is not great, but my jeep does almost no daily driving. Don't skip on little things like freeze plugs while you have it this easy to do.
Then is the cam and crank. The crank was turned 10-10 and repolished this is just to tighten up the bottom end and keep the motor smooth. Horsepower can be lost just by motor slop. The cam was custom cut by clifford. It is a 426 lift cam. They have the template for this and can be cut for anyone. they also go up to a 502 I think and lower also. This big of a cam needs a manual tranny or a stall converter to run and not shut the motor off. I got hydro adjusting lifters also from clfford along with pushrods. The bearings for both cam and crank are clevitte tri-metal bearings. You can order them or have napa order them for you. The 60 forged pistons came from york tool warehouse who can make or get just about any custom piston you need. I also got cromolly ring sets and shoulder pins from them. Remeber when changing cam or crank the bearings have to change accordingly. The connecting rods are original but have been smoothed and shot-peened. This again creates better flow. Also spend the extra money to have the bottom end balanced together. The machine shop will check the crank/rods/pistons to make sure they work smoothly together. Again power can be lost for sloppiness and engine balancing can fix that. The oil pump and water pump are reman originals as I don't need more at this time. Too much flow can be dangerous just like not enough.
The head is a factory head that has been redone, ported, and polished. New valves and double valve springs installed along with bigger retainers and locks. Most of that all came from clifford again.
That's about all the internalls, outside is a borla header, custom flowmaster exhaust, Accel 8.8 wires, blaster coil, poweraid tbs, injen ram intake, and optima batt.
That's about it. This took a lot of time but not tons of money and now my 2.5 is as powerful if not more than a 4.0 but alot lighter. I run down imports with 33's on and laugh. This is a big project though and without the right no how, You could spend a lot more money in having someone fix you mistakes, so make sure you are up to this kind of project before you start. If I forgot anything please let me know and I get back to you.