built 258 or crate chevy 350

my 74 cj5 232 has 93,000 on it and I'm looking ito a rebuild and need help. I'm looking at buying a crate chevy 350 with 250 HP and doing the comversion. After pricing all the adapters, modifications, and having to get a turboe 350 tranny, i'll be in about $6000-$8000. I don't know if it is worht the money. I definatley want more power but could a good build 258 do it. I want to be able to go in sand dunes and enough power to have fun. I can probaly get a good 258 for $3000-4000.

Can a 258 be built to have enough power and torque for sand? And about how much HP can you get out of a 258? If anyone has has the same delema, let me know which way would be the best. Matt

 

take a 4.0L, drop the crank and rods from a 258 in it. This strokes it to 4.5L. you can over bore it and get 4.7L from it. Much cheaper the the route you are looking at. Best news is you tranny will bolt right up and the engine mounts in the same spot.

Of coure you would need the fuel injection system from the doner vehicle of the 4.0 to make it work.

 

If you want power go V8. The 258 and for that matter the 4.0/4.7 motors are heavy for the power they produce. Tough, but heavy.

I went the 4.6 stroker route and its been a great motor on the trail and even the dunes, but it can't compare to a v8. I definately wouldn't consider the 258 motors seeing how the 4.0 are common and have fuel injection.

Kevo

 

If you have the $ to burn, go for the crate 350. IMHO, the crate is a little overkill, and is usually brought on by watching too much Horsepower TV on Spike.

The local boneyard is your friend. I am certain you can find a moderately used 350, and maybe one already mounted to a tranny/xfer case for a fraction of your budget. Don't be afraid of later model FI stuff. You can get computers and wiring harnesses to make it all work.

Check out jeepsunlimited.com and their 1970 "Unlimited" project. It has a 305 out of a vette, IIRC.

 

AMC 360? Maybe a gm 350 with 400 crank...383 stroker ooorraaahhh...

 

If you just want enough power to have fun in the sand, get a 4.0 and add nitrous to taste.

You'll be $2K-$4K ahead of the game.

 

AMC V8 or a Ford small block.
But if it were me I'd do the sroker I6.
If you want to freak folks out do the 4.7L stroker and super charge it too.

 

Thanks for all the replies. I think it will help my desicision...

 

Amonth or two back, JP magazine did a write up on a crate stroker I6. You might find it on their website.

 

The correct solution is the RamJet502.

1. No substitute for... well.. you know...
2. Fuelie out of the box. Add 12vdc and fuel = 500 HP.
3. Price...$9K is a bargain for this much motor. So what if it roasts all of your trans synchros...and your transfer case intermediate shaft...and eats spider gears...and you can't keep it cool...and there's no easy way to make it fit...and...uhm...never mind the 502...maybe you should think small block.

Having run a SBC all through Oceano, Dumont, Oregon and Mexico, if you can swing it I would no doubt go with the SBC. In the rocks, I'd listen to a I-6 argument, but not on the beach.

I also disagree with the target motor spike tv value comment. The Ramjet 350 is alum. headed factory bad@ss with a warranty and stand-alone EFI using a delco brain. I do not belive for an instant that you can get a 350 with a zero/zero overbore, alum. heads, injected and assembled from filter to oil plan for that money. IMO it's a great way to go for about 5K. Solid rebuilt Turbo350 (or 400 if you can make it fit) and the steel Rube Adapter and you are almost bullet proof. Down grade to a ZZ383 with the Holley Truck Avenger 750, save 2K, and you are still in the happy place.

Putting go-go juice into, or forced induction on top of, or whatever power adder you want onto a tractor motor can be done, but you can bet you $/cube/hp ratio will stink. The SBC is the most prolific HP motor ever made, with performance parts priced accordingly. And they sound cool at 4 grand.

 

All well and good, but still $3K too expensive, IMHO.

And this is from someone with a McCandless 380 Hp 360 in his Scrambler.

If you are building for the Dunes only, a '5 isn't your best bet to begin with...