Swapping 304 to 258 problem - JeepForum.com
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post #1 of 5 Old 06-30-2013, 06:31 AM Thread Starter
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1977 CJ7 
Join Date: Jun 2013
Location: Fostoria
Posts: 3
Swapping 304 to 258 problem

I have a 1977 CJ-7 with the automatic tranny. I've been reading on here where it is possible to swap the 304 out for a 258. I have change the flex-plate, changed the passenger side motor mount. Everything seems to line up great with one exception. I can not get the fan installed. The motor I got was out of a 1982 CJ-8. This motor has the serpentine belt. I even thought about and bought everything to change it out to an electric. Which will not work either. The E-fan is to thick. Got a fan out of a Taurus. I'm still using the 304 radiator. Any suggestions or help? Did I forget something? Here are some things I've done to the 258: Installed an HEI distributer, Installed a high volume low pressure oil pump, changed the wiring around for the integrated voltage regulator.

Thank you,

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post #2 of 5 Old 06-30-2013, 10:03 AM
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1986 CJ7 
Join Date: Nov 2009
Location: Devore Ca.
Posts: 483
I believe you have to move the mounting brackets back 1" to the next set of holes, same goes for the skip plate they are adjustable. The 304 and the 2>5 use the front holes because they are shorter. The serp belt is a good deal and came on west coast vehicles the only thing that you need to remember is the water pump is different it turns backwards from a Vee belt but identical until you look at the impeller, and the fan is also reversed, there are two ways that the serp belt will fit just make sure you install it correctly. Also the taurus/contour fan is almost a bolt on just trim the corners abit. but you are on the right track.

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post #3 of 5 Old 06-30-2013, 01:51 PM Thread Starter
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1977 CJ7 
Join Date: Jun 2013
Location: Fostoria
Posts: 3
swapping 304 to 258

I will look at that tomorrow. That will put my valve cover right up against the firewall( I do believe). I will have to look at the tranny skid plate and see if there is any room. I do not remember there being anymore holes back there. there is a set of holes on the drivers side to go back. thank you for the information and will let you know what I find out.


oh by the way the cj-8 the engine came out of came from the west coast (Utah & Arizona) .
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post #4 of 5 Old 06-30-2013, 03:00 PM
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1982 CJ7 
Join Date: Jun 2010
Location: Marysville, WA
Posts: 5,508
Forget the electric fan and put a stock mechanical fan on it and never worry about cooling or charging again.

Beat it to fit, paint it to match!

Wheel, Wrench, Repeat.
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post #5 of 5 Old 07-03-2013, 10:08 AM Thread Starter
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1977 CJ7 
Join Date: Jun 2013
Location: Fostoria
Posts: 3
Well I went and got a 6 cylinder radiator and installed the stock clutch fan. the clutch clears the radiator, but the blades still hit . My motor mounts as follows passenger side was changed out to the 6 cylinder one. rubber mount was in the center hole. the drivers side is on the first two holes and the rubber mount in the center hole. The Quardratrac rod for high and low from the floor to the transfer case linkage has two holes in it. it is on the back one. question is if I move the engine back an inch that will put my engine mounts off to the side of the steel mount. will I have to move the quardratrac linkage to the front holes?
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