Here's a fun article by Guy Yocum on what some instructors think Hogan's data would read if he were on Trackman:
The general consensus was a square path with a clubface about 1 degree left of the target.
I thought Sean Foley brings up a good point with of Hogan possibly zeroing out both the face and the path with him hitting the ball slightly off the heel.
The 'Hogan hit if off the heel' theory has been bandied about for years as anybody who has ever seen his personal irons saw a wear mark towards the heel.
The only issue with this is a better understanding of the equipment at the time.
For the longest time an issue that manufacturers had with equipment is that the epoxy was not strong enough to hold shafts installed in hosels by itself. They needed to use epoxy and then drill a hole on the side of the hosel to stick a pin thru to ensure the shaft would not come loose. You can see the pin hole on the picture above.
In order to do that, they had to make the hosels longer in length. You would see hosels vary from 2.5" to 3.5" in length. In fact, Hogan started to popularize a shorter hosel length with his Hogan irons. These days companies make their hosels much shorter. With muscleback blades, many OEM's will make the hosel longer because the blades player generally seeks a lower ball flight. However, the hosels are still shorter than the irons from yesteryear.
As the hosel length gets longer, the Center of Gravity moves up higher on the clubface and also moves more towards the heel. Thus, Hogan 'hit it off the heel' is a bit of a fallacy that was where the 'sweetspot' was located with those irons.
However, we should remember that the 'sweetspot' is essentially the size of a needle point and as great as Hogan was, it's not hard to imagine that he may have missed that spot on occasion.
I do tend to agree that Hogan likely hot a fairly low Spin Loft number:
Spin Loft = Dynamic Loft - Angle of Attack
The low Spin Loft has a tendency to produce high launch, low spin numbers with the driver. But, it's also characterized with better impact sound, smaller divots and less spin.
The issue with the old balata balls is that they used to spin like crazy (they also only lasted well for about 3-5 holes). Combine that with the grooves on the driver, that meant the golf ball was hard to control the curve for us mere mortals.
The only issue here is that Trackman only tells us so much and in the case of Hogan, it doesn't tell us nearly enough. There have been plenty of golfers that could hit similar numbers on Trackman and are nowhere near the ballstriker that Hogan was.
I tend to think what the article missed out on are other key aspects to Hogan's swing.
3-D Flat Spot
There is a 'flat spot' in the golf swing located near the low point. In recent years, researchers have discovered that there is a scientific advantage to having a longer Flat Spot. It can help with the Spin Loft, but also give the golfer more room for error in the process. I believe we tend to see longer flat spots with golfers like Hogan who had a pronounced lateral move in transition and then started to 'back up' their Center of Pressure as they go into impact.
I feel the video below explains a major difficulty of people trying to emulate Hogan's swing. Most of the Hogan copycats focus on the address position, having a flat backswing and a flat shaft plane in the downswing and trying to create this massive amount of lag. (along with wearing the white cap which is a must for a Hogan copycat).
But, what they miss out on is how much his Center of Pressure (aka weight) shifts towards his front foot in transition and then 'backs up' as he continues to rotate the pelvis and go into impact.
Vertical Swing Plane
This is one of the key elements that Trackman actually measures but was not mentioned in the article.
The flat shaft plane allowed Hogan to move and rotate his body like he did and that worked into an elongated Flat Spot.
Here at about p6, his left wrist is still in flexion.
And if there was anybody that got their Center of Mass of the club moving 'below' the net force of their hands...Hogan's swing was it.
Rate Of Closure
His pivot action helped ensure a slower rate of closure.
These factors helped Hogan reach those numbers and be able to do it with an amazing level of consistency.
That's usually what I find the problem with the Hogan copycats...they look at the wrong things and then to make matters worse, they try to emulate them to a tee. If they more carefully examined his hand path, wrist movements, lower body motion and his pivot in general, they could end up finding that golf swing they have always wanted...even if it looks nothing like Hogan's.