I have a similar set up so I guess since nobody has offered up advice I will help you where I can. Depending on the tools that you have yes you can do this without much problem.
Soak down all of the current Sammi suspension bolts / nuts good with PB Blaster, Liquid Wrench, etc. Plane on using both days of the weekend.
I have Sammi rears up front but Calamini 2" rears so I think my setup is comparable although the shackles are different because it seemes to me the CJ springs are a bit wider.
You will need to change your front bottom shock mount positions. I welded a shoulder bolt to the outside rear of the lower spring pad. This will allow you to retain the stock shock position.
You will also need front rear spring relocation pads or be willing to redrill the exisiting stock pads. (I redrilled mine)
Or you can purchase / fabricate your own front missing links. These would accomodate the axle moving forward. I didn't want thae axle moved farther front in the wheelwell so I opted differently.
The missing links would provide you with more flex and may better accomodate your rear spring width change.
Items you will need for this conversion are:
Extended brakelines 18" or longer depending on desired flex.
Extended shocks 21" or longer depending on desired flex.
2 - 1.5" driveline spacers.
3" drop Pitman Arm
Depending on your tire choice you may need to cut the outside tubular bumper braces to allow room for larger tire flex. You can relocate the brackets closer in on the tubular mount if you desire.
I removed mine all together and fabricated my own bumper.
Hope that helps you with your decision... maybe next time I do this I will have the underneath detailed... LOL...
