Jeep Strokers

I am wanting to use 4.2 crank and rods, and bore the block .060 over and get the corresponding pistons, yet every time i run compression ratio numbers they come up way high.... I want to run this on 91 pump octane maximum, i would prefer 89 or 87. I would like to know what you guys think about whether i should use the .043 head gasket, port the head, injectors, valve job, camshaft, everything and all details like that. Sorry but explain it to me as if i were an infant.... im still quite picking this stuff up after months of research.... Thanks for your help guys. Also this is kinda on a budget.... so we cant go out of the world on prices.... I know im asking alot..... but thanks guys.

You could do a close copy of the 4.7L medium buck recipe in my site.

Would i have to use the 4.0 rods and the 68mm throttle body?

1991YJ wrote:Would i have to use the 4.0 rods and the 68mm throttle body?

You could use the 4.0 rods/IC944 pistons in the recipe or go for 4.2 rods/H825CP pistons for the same 9.6:1 CR but with a higher quench. A 62mm TB will suffice.

I plan on going with a 65mm mustang tb and i will do some research on your setups... with a 9.6 to 1 cr can i run 89 pump gas? Also i plan on posting the head to match the intake, and also porting the cumbustion chamber around the valves, cant i reduce the cr that way if i want to lower my quench?

1991YJ wrote:I plan on going with a 65mm mustang tb and i will do some research on your setups... with a 9.6 to 1 cr can i run 89 pump gas? Also i plan on posting the head to match the intake, and also porting the cumbustion chamber around the valves, cant i reduce the cr that way if i want to lower my quench?

The answer to both questions is yes but be careful when unshrouding the valves that you don't cut the edge of the combustion chamber beyond the margin of the head gasket bore.

1991YJ wrote:I plan on going with a 65mm mustang tb and i will do some research on your setups... with a 9.6 to 1 cr can i run 89 pump gas?

Doubtful unless you get a can that reduces your SCR.

Also i plan on posting the head to match the intake, and also porting the cumbustion chamber around the valves, cant i reduce the cr that way if i want to lower my quench?

You will most likely not be able to remove much material from around the valves. You would have to remove quite a bit of material to make a noticeable difference in your compression ratio.