motor question

87yjinCincy · 08-24-2007, 11:13 AM

Are the 4.2 AMC motors from the 79 CJ7 any good?

KargoMaster · 08-24-2007, 11:23 AM

The straight 6 AMC 258 has a following of loyals... Some with the smaller 232 swap them in for an improvement in performance...

Same bolt pattern as an AMC V8 I believe...

Hope that helps...

87yjinCincy · 08-24-2007, 11:37 AM

This may be a crazy question but is it a better motor than the straight 6 4.2 that's in my 87 YJ?

94Dodge Truggy · 08-24-2007, 12:32 PM

I believe that the pre 75 4.2's are sought after. The 4.2 weighs 110lbs. more than the 4.0. Combine parts from both and make a stroker. To be as paticular on a year for the motor as you are would only be worth it if you were planning on making crazy amounts fo power from it.

08-24-2007, 11:13 AM	#1
87yjinCincy Jeep Noob Join Date: Aug 2007 Location: Blue Ash Posts: 21	motor question Are the 4.2 AMC motors from the 79 CJ7 any good?

08-24-2007, 11:23 AM	#2
KargoMaster Cleaning off the rust... Join Date: Jan 2007 Location: Cincinnati, OH Posts: 1,009	The straight 6 AMC 258 has a following of loyals... Some with the smaller 232 swap them in for an improvement in performance... Same bolt pattern as an AMC V8 I believe... Hope that helps... __________________ brad 5.0L \| 435 \| 203 \| 300 \| 4.10 \| 39.5 Buildup BACK underway...

08-24-2007, 11:37 AM	#3
87yjinCincy Jeep Noob Join Date: Aug 2007 Location: Blue Ash Posts: 21	This may be a crazy question but is it a better motor than the straight 6 4.2 that's in my 87 YJ?

08-24-2007, 12:32 PM	#4
94Dodge Truggy EX-Vice President Join Date: Jan 2007 Location: Fairfield, Ohio Posts: 3,048	I believe that the pre 75 4.2's are sought after. The 4.2 weighs 110lbs. more than the 4.0. Combine parts from both and make a stroker. To be as paticular on a year for the motor as you are would only be worth it if you were planning on making crazy amounts fo power from it.