Mopar 318 heads
Before we start off you'd probably be better off with a good running 5.9l magnum.
The base Hp/TQ is a stock longblock 5.9l with 4bbl and headers.
Getting that out of the way, there's a 318 build stock long block "low cr" 4bbl headers and a comp cam xe262 making 282hp at 5000 rpm.
After that the problem with 318 is it's cr, limits the size of the cam you can use and 318 head flow limit the power you can make, could use 340/360 heads but they will drop the cr even more.
Magnum will give you enough air flow to make 400 hp, but you might as well use the whole magnum engine, porting 318 is an option if you can do it, but you could probably buy some aftermarket by time your done sinking money into the stock head that might flow as good as a 360 1.88 valve head.
Before we start off you'd probably be better off with a good running 5.9l magnum.
The base Hp/TQ is a stock longblock 5.9l with 4bbl and headers.
Getting that out of the way, there's a 318 build stock long block "low cr" 4bbl headers and a comp cam xe262 making 282hp at 5000 rpm.
After that the problem with 318 is it's cr, limits the size of the cam you can use and 318 head flow limit the power you can make, could use 340/360 heads but they will drop the cr even more.
Magnum will give you enough air flow to make 400 hp, but you might as well use the whole magnum engine, porting 318 is an option if you can do it, but you could probably buy some aftermarket by time your done sinking money into the stock head that might flow as good as a 360 1.88 valve head.