Engine 1980 CJ-5 Engine questions

[Jfox195]

I have recently purchased a 1980 CJ5 . It has a 6 cylinder engine in it, with a 4 speed Transmission . Original plan was to swap engine out with a Chevy V~8
Time and money are now becoming a consideration as to which way we go with this. I have a few questions :
1. I have read that (or I think I have) the only engine that came in the 1980 CJ5 was the 4 cyl Iron Duke ?
2 So IF that is the case this was an engine swap, but I should assume that its a AMC 258 i6 / 4.2l ci ?
3 Has anyone reading this have any experience with engine builders / suppliers of mild high performance 258 ci Six cylinder engines ?

Thank you in advance for your replies. Im very new to Jeeps and look forward to working on this one.
Jeff

 

[Manic Mechanic]

No there were a ton of options in 1980 including but not Limited to

134 cu in (2.2 L) Willys Hurricane I4 192 cu in (3.1 L) Perkins Diesel 4.192 I4 diesel 225 cu in (3.7 L) Dauntless Buick 225 V6 V6 GM 151 cu in (2.5 L) Iron Duke I4 AMC 232 i6 cu in (3.8 L) AMC I6 AMC 258 i6 / 4.2l cu in (4.2 L) AMC I6 AMC 304 cu in (5.0 L) AMC V8

Sent from my E7110 using Tapatalk

 

[CJ]

The AMC 258 i6 / 4.2l is a great engine and has a fair amount of torque and a longevity.
It's a keeper IMHO.

 

[Jfox195]

OK so after some consideration, I'm going to stick with the 6 that's in the Jeep. Hoping to find out if its original. I have read where the 1980 was a year of change from the heavy 6 to a lighter engine with aluminum intake, which this one has. My question is what number on the engine would say what year the engine is and where would it be located ? Thank you

 

[Jfox195]

Our new baby...

 

[Belizean]

Clean looking

 

[TSB8C]

OK so after some consideration, I'm going to stick with the 6 that's in the Jeep. Hoping to find out if its original. I have read where the 1980 was a year of change from the heavy 6 to a lighter engine with aluminum intake, which this one has. My question is what number on the engine would say what year the engine is and where would it be located ? Thank you

I believe the engine serial number is stamped on a machined surface located on the right hand (passenger) side between cylinders 2 and 3.


I also believe the date is on the block on the driver's side near the front and a bit lower down than the serial number on the right side. The date code shows the day of the year as a 3-digit number (i.e. 055=55th day of the year) and then the 2-digit year itself. Here's an example showing "055 87" meaning the 55th day of the year in 1987. That would be Feb 24, 1987.