engine swap

I have a 1954 m38a1. I want to put a 258 in line six into it. I have been told this is major project. I have a T19 trans. I also have the front end off of a 79 postal jeep with the extended grill.

 

very poor choice of engine for a short fender swap. The straight sixes are just too long to be practical or logical.

JB

 

the reason for the 258 is I have a rebuilt one already.

 

If it were me, I'd sell it and get something else even if you lose money on the deal. They don't fit well at all in the smaller engine bays, and I don't think they were very desireable engines anyways. Go with a Buick 225 or 231 if you can find it, or a newer chevy 4.3 with fuel injection. I would go with a 4.3 if I were doing it, just because I'm really jealous of people with fuel injection.

 

in order for it to fit, you need a later frame, hood and fenders. would br time and $$$ ahead to sell the 258 and go :v6: .

 

Not to mention weight. That I6 is a boat anchor.

 

In general, inline 6s are a poor choice for the CJs before 1972. To make it fit, you'll need to move the firewall back to accomodate the engine length. I understand that the bubble grille should provide enough room for this engine, since the 232 fit in the 81" WB mail Jeeps. However, IMO you'll still have to modify the frame, and you may end up with a result that you're not happy with, and which you'll have trouble selling. (You may think now that you'll never sell it - that's what everybody thinks, and they're usually wrong).

The 258 is a good engine, and it is not much heavier than the usual choices for early CJ swaps. The early (pre-1981) 258 is about 500 lb, and the later 258s are about 80 lb lighter. This compares to 575 lbs for a Chevy V8 and maybe 414 for the oddfire Buick V6 ... about par. Very few cast-iron motors are under 400 lbs. I'd guess that the Kaiser F4 is between 550 and 600 lbs; weight distribution will not be good with the 258 way forward though.

Which vehicle did the T-19 come from?

 

There's an old saying in the swapping/modifying business. "Just because you have it doesn't make for a good swap". Truer words have never been spoken. Save the engine for another project or sell it and find a good V-6 to put in there. There was a reason AMC went to longer fenders, hood, and frame in 1972 and that was to accommodate the longer 232/258 engines and later the V-8's. Nickmil.

 

i think he should put a mazda twin rotor rotary engine...it prolly has 5.38's already so you can wind it 12000 RPM all day and be able to make 55 mph down hill in a windstorm. with the mazda engine only weighing like 27 lbs, would make that jeep dance across the mud. and plenty of hp.

just kiddin!...0=)
go with the v-6 bro, or a 4 cyl diesel/turbo diesel. the 4.3 is a nice choice, but its distributor is in the rear which will hit your firewall and make tuning a STRETCH. a buick v-6 has the oil pump, distributor, oil filter, and everything sticking out of the front for easy access. you can pick up an evenfire very cheep and itll run smooth and have good power then bolt it to a RWD bell housing and your choice of 4-speed rawk crawler trannies (or nasty automatic) and go like hell. odd/even doesnt matter really..most like the vintage sound etc. or they say its stronger (alittle bit), but the shear quantity of even lying around will amaze you.

or, dig on a 4.1 (252 evenfire) from a caddy or bigger buick between like 81-83 or so and get even more power (make sure you have good colling with this one cause it was cast like a 400 SBC with the siamese cast cylinders and some say it over heats). 4.3/4.2/4.1....same CID motor, different shapes. in my humble opinion (unbiased), the buick 231 is a damn fine engine for your (and my) application. i bought a dauntless 350 to shoehorn down in there, but damn the cutting and welding required...it just wasnt worth it. i will put it in a cherokee (68-70 or so) and be done with it. check out the evenfire. itll do you right everytime.