Help with engine choice '64C

[BK911]

Hello!

Currently have a mystery engine installed in a '64 coupe.
There are no stampings on the case.
The cams are a SC/912 grind.
Carbs are zeniths.
Heads do not have the vent hole, but from limited research the C/SC/912 heads were pretty much the same.

Just a guess, but I am thinking I have a SC spec bottom end with zeniths carbs.

A very, VERY nice '69 912 engine with the 1720 P/Cs just because available.

Power wise, easy choice!
What about future resale?

Is an unstamped case more valuable than a 912 engine in a C coupe?

Trying to figure out which direction to start heading in.

[Miguel Antonett]

IMO, a non matching number car is a non matching number car. You take it from there...

However, what's the real meaning of a matching number car?
None to me, it really depends on each individual car... furthermore, there is a whole set of stencils out there that can take care of that - seen it with the market trend = FRAUD.

My car is not a matching number car, but I'd be delighted to put it beside many matching number cars and be proud of it, and performance wise even more...

One thing is the market and another thing is enjoying the car and sometimes those two things don't match. M2c

[callard]

Looks like you have a C engine that has at least the third piece replaced. If there are no stampings (such as 616/XX) on the case halves along the top bolt flanges then the whole case was replaced. The SC and 912 have a counterbalanced crank while the C does not. You can't tell unless you pull the P&Cs to take a peek inside.
The Zenith intake manifolds aren't as wide as the Solexes (SC and 912) and the sheetmetal pieces that the manifolds go through are different between the two engine types. I rather doubt that someone put Zeniths and manifolds on an SC engine just to gain a pair of Solexes.
Numbers matching is desirable to some. Numbers fraud isn't.
You can put the 1720 kit on a C engine with Zeniths and it is a very smooth running tractable engine with low end grunt (lighter crankshaft), The SC/912 breathes better at higher RPMs but gives away a bit at the low end. TANSTAAFL.
Either way, Enjoy!
I forgot to mention - you have a 912 type oil filler can rather than a C or SC.

[Speedster56]

The crank can be inspected by removing the sump plate on the bottom of the case. Remove the strainer and you get good view of the crank and will be easy to tell if the crank is counterbalanced or not.
Your question is not that straight forward actually. Both the C and the 912 are nice motors if they run properly and are constructed with the correct parts. Knowing who built either your current engine or the 912 may be a good guide as to what is inside.
The condition and originality of the heads, crank and P&C's I would think should guide you on the overall condition of each motor.
If your unsure, and can swing it, I would buy the 912 to assess, then you could either sell one or keep the 912 as a spare. It is unlikely you will loose on the transaction as long as you don't overpay in the first place.
The other thing to always remember. Used motors may look good and sound fine, but there can be bad things lurking in the case. For the price of the 912, you may be able to do a good rebuild on your existing motor and end up with a very nice motor, and, you know what is inside it and who put it together.
One last thing, if the 912 came from a 912 model, the flywheel is not compatible and would have to be swapped with a "C" flywheel.
Nice problem to have.
Geoff