well i have figured my options, and here they are
1. buy new head from mercedes for $1,700.00 that will still require some parts and minor assembly and prechambers $110.00 ea) likely well over $2,500.00when done

2. get an assembled new MB unit from metric motors for $2,850.00 minus prechambers $110.00 ea) well over $3,000.00 when done

3. i found a good used 603-016-18-01 for about $650.00, donor car had 190k miles, no cracks in good shape. i figure i can get it rebuilt and be good to go for around $1,500.00

so within my $1,500.00 budget i will get the head and rebuild it and replace timing chain and vacuum pump and cover all other parts related to the cyl head replacement

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1967 250 S
1967 280SE
1968 250S
1971 280 SE
1973 220
1974 280 S
1975 450 SEL
1976 220 D
1979 300SD
1983 300 SD
1985 230 TE euro
1986 280SL
1986 500 SEL euro
1986 190E 2.3
1990 300 SE
2003 C230 K
2004 C230 K
1987 560SEL
1987 300SDL now in canada
2005 C230
1998 C43 AMG Sold to DON
1993 190E 2.6
300TD Former daily driver Totaled
current:
R320 CDI
Ram 2500 Cummins