I'm looking for a early 70's 6.3 or 6.9 engine and trans for a hot rod project. The guy I used to work for has an early V8 he swapped out several years ago, he THINKS is a 450 SEL. How can I tell the difference between the high horse 6.3 & 6.9 and the lesser horse 4.5 ? I have always been confuzicated by M.B. badgiung because it never seems to have any bearing on engine displacement

engine designation is M100 and was found in 70 450SEL featured a dry sump oil system as well

Additional question. Did all of the 6.3 6.9 engines use the " log " style intake runners? The engine he has has a low profiule manifold with the t.b. in the center and the whole intake setup sits barely above the cam covers.

That designaiton is only for the larger displacement engines? And where would it be located on the block ?

6.9s were dry sump, or so I've found on Google. Pretty easy to i.d. THAT! CIS injection. The 6.3 had 2 long kinda tubular intake manifolds that come together at the throttle body in front of the right cam cover. Identified as the M100 engine, and there are numbers somewhere on the left side of the block, as I recall. Maybe at the flywheel end. The Cap'n

Yup the rumnner are what I referred to as " log " style. I have a pic of one I know to be a 6.3. Problem I have is identifying the engine my friend has. His does not have that style intake but he says it is a 450 sel. I'm assumoing it may be a later style with a different intake ? I'll try to get a pic tomorrow if I have time to go that way. This IS a 1970 300 sel 6.3, and I beleive the 6.9 looks the same. I want this style not nly for the H.P. but the runners would be very easy to cap the ends off, reverse the stance and put an adapter plate for a carb...or 3....... Hot rod ya know, I can't run messy F.I.

Intake option 1. pretty easy to make

Well after a bit more research I found a pic of the intake on hois engine. The guy says it is off of a 4.5 FUCH. My friend also has a complete car we used to bomb around in, all I remember is it was FAST. I'm guessing it has the larger engine. I'm alsoi guessing it could be mine since he has a 911 he wants painted

Pic of the 4.5 intake FWIW

Geeze, you guys are spoiled ...


Back in the early '90s, i had a 280 SE with a 2.8L /6 and i thought that car was fast ...
Andy

How's that 1.7 running ?

Here's a low quality photo of a 6.9. The intake you have is a 4.5 style with EFI.

The Cap'n

I had a 71 300sel with the 3.5L/8 and i thought that was fast. It had the same type manifold with the downdraft throttle body as that one pictured as it was EFI.

Pops had a 6.9. That car was fast. Faster than my SHO and that was fast.

Put that cross-ram on it! (ooooooooops sorry, wrong post)

I'm gonna find a cross ram ...turn it sideways and shove it sqwah up yer arse !!

The 300 SEL 6.3 and 6.9 were serious sleepers.

That does it Mister. From now on we require you use your real full name on this site!

Big Dick McGee