This might be helpful for those who want to have a quick release (QR) steering wheel capability and are stymied by the complexity challenge or like me, love the ERA approach Patrick selected but aren't up to swapping steering columns or writing the $850 check for what is one of the nicest implementations I have seen.
At the front of the conversion parade we are met with a steering wheel attachment bolt circle problem. Virtually all of the steering wheels and QR systems today use either a 6 bolt 70mm or a 75 mm bolt circle for steering wheel attachment. My SPF appears to use a 6 bolt x 64 or 65mm bolt circle. My inquiries to MotoLita indicated that their original (and current) Cobra steering wheels use a 6 bolt x 62mm bolt circle with unequally spaced bolt holes! As luck would have it, either one is an attachment problem.
My requirement for the QR system on my car was to be as close to invisible as possible, the same steering wheel position if at all possible, no detectable play in the attachment between the steering wheel and the steering column shaft while driving and easy of use. Reasonable pricing was an unspoken but intuitively sought after additional goal.
I think I have found a reasonable compromise that might work for other folks also. This is how it is done.
The QR adapter I found most attractive was the low profile NRG SRK-400BK unit because of its low height (24mm) and its tight (locked up) condition when the wheel and column are coupled up. The actual unit is available in black, silver and a bunch of other colors. Once installed the black and silver color options nicely hide the presence of the QR system, making it look like either a part of the steering column or the steering wheel. It is easily missed / invisible unless you deliberately look for it.
This is what the actual QR coupler looks like with both pieces, assembled. This is the steering wheel side. It is drilled for both a 70mm and a 75mm steering wheel attachment bolt circle.
And this is the steering column side;
The unit supports a center horn button and while I suspect you could wire it up with sufficient motivation it might be easier if you don't — as you'll see later.
We are still plagued by the wrong steering wheel bolt circle problem but fortunately there is an easy fix. It involves modifying the steering column hub the original wheel bolted to.
The pic below is what our steering column hub looks like. The picture is actually a hub off the Branda site that is not painted or anodized black yet. But it illustrates the geometry which is what is important.
Notice the convenient recess the spline register and attaching nut are sunk down into. To get the steering wheel into the original position you will machine off 24mm of aluminum and redrill the hub, but this time for a 70mm bolt circle, I believe. I need to measure my QR adapter when it arrives. That will place the top of the QR adapter at the same level as the original steering column hub attachment surface was at. That is the good news.
The bad news is the QR adapter steering wheel mounting surface is drilled for a 70 or 75mm attaching bolt circle. You have two choices. The least expensive (but a little more work) is to redrill your original wheel for the new bolt circle. This will probably work but requires a little reindexing of the QR mechanism to get the wheel straight up again.
The other choice is to just buy a suitably good looking replacement steering wheel for the finished job. I went the later route. If you are into more closely approximating the original appearance of the wheel, this particular wheel is available off Amazon as either a 14 inch or 15 inch variety;
It is not exact, but it is close ~ $150.
If you have big hands, prefer a thicker wheel rim to hold on to and want a wood appearance this wheel is a ~$63 item that will nicely fit the bill. It is also the wheel I chose;
I prefer a cushioned leather wrap as opposed to the, harder to the touch, wood finish and I prefer the larger diameter rim grip on this wheel compared to the more original looking alternatives above. For about $10 more you can buy a genuine leather cushioned wrap, which you will get to personally stitch up (stitching holes are already punched out).
This route takes a little more effort (especially if you decide to go the leather wrap route) but saves a whole bunch of money. BTW while searching for a replacement steering wheel online, I found an unbranded version of the NRG QR adapter on eBay, The cost is ~$30. Here is the link, click here =>
QR Hub. The black adapters are currently out of stock, so if you want black there will be some sort of restocking wait — other colors are in abundant supply.
Almost forgot, my comments about the horn button wiring;
If your steering column hub does not have a deep enough well to machine off 24mm of aluminum and still clear the steering column shaft and nut, you can still use this system by unscrewing the horn wiring pcb and allowing the nut and steering column shaft to rise slightly up into the center of the QR assembly.
Ed