89' 300SE vs. 93' 500SEL

[86560SEL]

I know there is a world of difference between the two - one is a different generation - shorter wheelbase, 6-cylinder model and the other is another generation - longer wheelbase, 8-cylinder model. I have a 1991 Lexus LS400 thats totally bulletproof and I am crazy for wanting to sell it/trade it, but I want another S-Class Mercedes. I found a local 89' 300SE with 171K thats in EC for $2700 and 1 1993 300SE with 181K for $5900 AND a 1992 500SEL. I know - I need a PPI before purchase. Have some questions though.

I know the common problems on both and as far as reliability/maintainence costs, I would probably be better off with a 89' 300SE - right? I know of the horror stories about the evaporators, wiring harnesses and driveshaft problems on the 92-9? S-Class. Well, I did a search and could find no answers to my questions below.

I know that the W126 V8 models have interference engines and require timing chain (as well as tensioner, guide and rail) changes after so long to prevent catastrophic failure. I am wondering do these other two cars also have interference engines and require this work to be performed? I am thinking yes on the V8, since this was the case on the W126, but not sure. I was hoping they had changed to "metal" guides and rails... lol.

I talked to a guy with a 1994 S420 and he said he has owned several V8 80s and 90s Mercedes and never changed timing chains, etc and never heard of this being a problem. I told him I thought it was preventative maintainence and not so much the chains, but moreso the guides and rails get brittle with age.

Thanks in advance.