258 or 304 rebuild

i know this has been covered before. but i cant quite find all the info i need to make a decision...so here goes...
i am planing to rebuild a motor to put in my jeep, right now it has a 258/t14/d20...i am planing on replacing the t14 no matter what i put in and maybe the d20, but im not sure about it. i am going to be building the engine peice by peice while still running the jeep. i dont need huge power or anything, but i am going to build it for "performance" either way, i will be putting tbi on it too. i am not too worried about cost but i am concerned w gas milege as it will be driven to the trails not trailered. also i want something that will run forever. i need some ideas and info, thanks.

 

If your going to do FI anyway why not go with the 4.0L head and MPFI?
Keith

 

how much more expensive and complicated is the conversion

 

Couldn't tell, I've never check. But I think Chrysler makes a kit.
Keith

 

Last I looked the Mopar MPFI kit was about $2000.

I'd stay with the 258. The AMC V8s are good engines, but the AMC inline 6s have a much better reputation for longevity (edit - was reliability, but a fresh 258 and 304 are probably equally reliable). Very few other engines are (arguably) more reliable or durable. Plus they are widely available cheap or even free, and parts are easy to find and cheap.

If you want ultimate performance, skip the 304 and go directly to a 360, or better yet, a 401. The price/performance of a 360 will be much better than a hopped-up 304. Building a 401 could be pricey, but unlike the 304/360 it has a forged steel crank, forged steel rods, and a strong, high-nickel block - a much better starting point for a performance engine than the 360, and significantly more power than a 360 in stock form.

Certainly a very mildly modified 258, with an RV cam, 4.0L head, HEI, low restriction single exhaust, and either TBI or a 2V carb on a '80 or later 2V aluminum manifold will make as much power as a stock 304, and make more torque at a lower RPM.

 

thanks guys that was the experience based info i was lookin for.
258 it is....they really are hard to beat and harder to bust

 

owner of a 72 commando, 258, 80,000 original hard miles,no other vehicle in the family made as much trips to camp, 800 miles pavement round trip, 100 miles dirt,river and washed out culvets, I can't say enough about it or kill it.