Sorry I might have been confusing here. I should have wrote this "we are talking headers here to add HP, not changing the heads to add HP."

If you already put headers on, are you running dual exhaust? And you can gut the cat or take it out entirely for a little more boost. Electric fans are in the FAQ as another upgrade you might consider. Underdriven pulleys also. You can also change your spark plugs to autolite 3923s, although I don't know how much HP you will gain over what you have, but our trucks do run good with them.

I have a Mopar Performance computer in my V6, and it definately makes a big difference. Somone feel free to intervene on me here if I am wrong, but the MPC basically adjusts the timing on your truck resulting in a boost in HP. Our trucks are not able to have the timing adjusted unless you have a carb, which I don't know what year trucks they came in. Can't speak first hand about the JET chips, but I also have not seen rave reviews on them. not exactly sure how they are supposed to work and what they change.

Aside from that, I think anything else you do will have to be a little more than bolt on improvements, like boring out the cylinders, changing engine components, etc.

 

the jet chip makes a little more power, but not worth the money. and i agree too with the heads, intake, throttle body, spacer, and all the other stuff i could not read not giving you any horsepower. and you will need alot to outrun a v8 mustang, i have even seen the new ones with stock v6 run in the high 14s

 

hmm If i were to sum these up, I would have to say, if you want more power with parts from a 360... put in the 360.

MPC is the next easiest performance gain over the no-brainers (air-cleaner, exhaust ect.)

otherwise there's no replacement for displacement (w00t first time I get to use that!)

fancy intake's, cams, and shiny ported heads will do the job too, they're just hella expensive (peruse hughes engines if you want to get a good idea at the top end options...)

there are a number of threads regarding the aforementioned engine swaps, as well as a few stroker builds, here in this forum, and they're pretty abundant throughout the rest of the internet as well...

 

I would say if your 318 runs good and still has some life, dont be impatient. Buy which ever 360 is most complete and you can afford, strip it down and either build a 408, or just clean it up. Paint it, new gaskets, and maybe do some headers, cams, performance intake, and then a mopar ECM. Then drop that bad boy in you truck

Good luck