If you want to transplant an American V8 into your chassis, a small block Chevy would be a poor choice. The oil pan sump is at rear on a Chevy, and your Mercedes engine has a front sump. The distributor on the Chevy is at the rear, too, and would be troublesome to fit against the firewall.
A small block Ford, like a 302, would be a better candidate as the distributor and sump are at the front just like your Mercedes engine.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".