V-8 Cylinder Head Interchange

[SLacker]

For the V-8 engines made in the 70's, can anyone comment on:

1. Are the heads for a 450 SE or 450 SEL (117.983, 117.986) the same as the heads used for the 450 SL and 450 SLC (117.982, 117.985) of the same year?

2. Are the heads used on the earlier electronic fuel injection engines of that group, the same heads that were used on the later mechanical fuel injection motors?

Thanks.

[david s poole]

#1----yes #2----no

[SLacker]

Thanks for the response David.

#1 - So why different engine numbers? Is it only that they are have a cam profile to suit a different weight car?

#2 - Is it practical to convert the earlier to the later? Just add a sensor port or is the injector hole different?

Thanks again.

[david s poole]

sl engines had one pce oil pan hence diff # the k jetronic heads have cut outs for the k-jet injector cups.

[cth350]

the other notable difference in heads over the years is the addition of hydraulic lifters. -CTH

[Tomguy]

The best upgrade to an older 4.5 (be it D-Jet or K-Jet) is to put on the correct corresponding 3.5 heads. Higher compression. Don't do it in a state that would still require emissions testing, though.