You might have better luck at a Cobra website, as to differences between various replicas, what to watch out for, etc. And for engine-specific questions I would suggest fordfe.com and fepower.net. They can give you tips on how to identify a true 427 center oiler vs. plain jane blocks. You want to avoid a bored out 390 (walls too thin). I think there are a lot of counterfeit engines out there so it pays to be cautious. And as Extech said, all the FE engines are the same dimensions externally.
Well, the 427 was the top of the line FE engine from a performance perspective. The compression ratio might be higher than what you'd normally want but then again, the car is likely light enough that it is not a problem, on premium.
Most of us have not driven a Cobra, real or replica, so it's hard to advise someone on the weight balance. And most are hesitant to say strongly one way or the other when it's someone else's money and likely a lot of it. That's kind of why I was suggesting a Cobra-specific forum. There are probably already discussions of this nature from the past so you might just search.
As for reliability, do you know anything about the cam? Solid rollers aren't supposed to last too long on the street from what I've read. I think the jolt from the valve lash wears out the axle of the rollers. The other combinations (solid or hydraulic flat tappet, hydraulic roller) are supposed to last longer. Again, really hard to give specifics, but 427s won Le Mans twice, running high RPMs for hours on end, so it would be hard to say they are unreliable. I believe those were side oilers vs. center oilers, but the difference only comes into play in that scenario (sustained high RPM use). Nothing wrong with center oilers at all.
If it's documented (the engine build) and in good shape, and you want a Cobra, then a 427 would likely be my first choice.
I had a Classic Roasters Cobra replica with a 408 Windsor Stroker for 14 years and it was fun and quite potent!! I've always heard that the weight of BIG BLOCK Fords was detrimental to Cobra's handling performance but I don't race so that's not an issue!!
Here's what the seller says and I plan to call to get more details!!
535 thundering horsepower]; expertly and painstakingly rebuilt; the rebuild was completed on 10 March, 1999 by highly-respected Aldridge Motorsports & Engineering in Portland, Oregon.
Holley single 4-barrel 780–735 cfm with electric choke, roller cam
10-qt. oil pan
Edelbrock aluminum FE heads & roller rockers
Edelbrock aluminum manifold
MSD ignition ensemble
Griffin high-capacity aluminum radiator
pusher-puller fans, thermostat-activated
balanced, high-performance thermostat [much more accurate than spring-type thermostats]
Ha, then you are already way ahead of us Cobra-inexperienced peons. Did your Windsor stroker have aluminum heads? Either way, the FE will likely be heavier but if the Windsor had iron heads, the difference would be less. It says roller cam - I'd be asking more about that: solid or hydraulic, specs, etc. And the transmission and axle (9 inch I guess). Also how much it's been overbored (wall thickness). But yeah, if the engine was built good and in good shape, I wouldn't be concerned. Parts for the FE are expensive (crank, heads, pistons, intake, etc.) compared to the Windsor (or most engines, actually), but not really a big concern since they are already in place. Other than that, just like any other car purchase - price, condition, distance, etc. Lots of things to weigh. Good luck with it.
Everyone always quotes the "weight on the front" to be a detriment, but if I recall, Ford/Shelby didn't have any trouble back in the 60's winning races with them. In addition, next time you have a hood open on a Cobra, look at how far back the engine sits in relation to the front axle centerline.
As for the engine, here's what I see:
1. It's not a side oiler, which is what everyone craves in a Cobra.
2. It's a center oiler. In a lot of instances, center oilers do not have oiling to the lifters, which means that if you have a roller camshaft, it's a solid roller camshaft, and if it's a solid roller camshaft, the lifters will last about 7000-8000 miles before needing to be rebuilt. The first thing I would do would be to call and ask if the block is setup for hydraulic lifters or not. If not, it's not a deal breaker, but it may be more maintenance than what you want in the future.
3. Edelbrock heads are not high end heads anymore. They are actually the bottom-feeders of aluminum FE heads these days. You can CNC port, you can change valve stem diameters, etc., but this may be something you should inquire about as well. Are they ported or are they stock?
4. A 427 Cobra engine with aluminum heads will look out of place if you're going for looks. Most of the time, when guys have me build Cobra replica engines, they are period-correct looking for resale value.
WHY pass on it??? Just plan to do a cam & lifter change after 5,000 miles to regular solid flats... Cam lifters & push rods.. no big deal. HOW MANY flat tappet solids have been run 100,000+ miles... A LOT of the 27 top oilers were marine engines that ran 3,500 - 4,000 rpm for hours on end all uphill WITHOUT any problems for years. Side oilers were for extended 5,000-7,000 rpm at race tracks. And the 427 LeMans engines were a very special "one off" not regular 27SO. HOW MANY top oiler FEs have been run on the highways and dragstrips for the last 60 years WITHOUT issues? Are you going to make this toy into a serious vintage racer? Only place today you might see extended high rpm. Buy it and have fun.. maybe by the time you need lifters there will be much better ones available. or not... alll I think about are your miles of smiles... jealous..
That would be fine if he immediately brought it home and swapped cams. But we don't know how many miles are on it, and it's not like the lifters only fail at a specified mileage....they can fail at any time and when that happens, it tears a LOT of stuff up.