Cold light question

I'm in the process of converting either an 8x10 enlarging camera or a 5x7 Elwood into a 5x7 cold light enlarger.
My question is: how close does the light source need to be to the negative?
I know that using the 8x10 enlarging camera, I can get the 12x12 Aristo head that I'm using right on top of the negative, but with the Elwood, which I think will make a much easier to use enlarger, I'm not able to get the light source closer than about 3 inches from the negative.
Is that distance going to be a problem?
hanks in advance for any advice

I have the 1212 and mine sits about an inch above the negative. Ideally, you want the head to be as close to the negative as possible. The 1212 is a big head so you may get away with it.

The general practice is to have the diffuser under the cold light sitting up close to the negative. So I agree with Andrew.

Thanks Andrew.
What enlarger are you using?

I just measured the distance from the negative to cold light bulb on my gear

Beseler 810MXT with Beseler cold light head 2 3/4 inches.
Beseler 45VXL with Aristo cold light head 2 3/4 inches
Durst 184 with Aristo 10x10 cold light head 2 1/2 inches

The diffuser on all three is within 1 inch of the negative.

The Durst importer mounted the Aristo Coldlight on my L1840 about 3.5cm above the negative holder. The edges were still dim, so I re-mounted the diffuser panel even lower.
http://www.largeformatphotography.in...l=1#post319616

At 3 inches I'd definitely want a second diffusion sheet closer to the neg. But everything
depends on high tightly the tubes in the cold light are configured. My own Aristo 12X12 is
about an inch above the carrier.

My plan was to remove the original diffuser and put a new one directly above the negative carrier. It looks like I'll be able to get the Aristo head closer to the negative carrier than I originally thought that I could.

mccolaix, my 8x10 enlarger used to be an old large graphics camera that school I teach at was getting rid of. We used it to make positives for the yearbook. That's all digital now.
I stripped it down, added a 240 Schneider on the bottom, a negative and filter tray and the 1212 on top. The whole thing was wall mounted. Has worked well for me for several years. My Aristo 4500 (on a 4x5 Fujimoto enlarger) head on the other hand, sits directly on top of the negative as this head just covers the format. Even if I lift it up half an inch, vignetting occurs.

As close as possible.

I have a 45 MXT to 8x10 conversion. I mounted a Radeka masking negative carrier between the VCL 8100 light source and the 8x10 adapter flange. Works well.