I am considering getting these forks: http://www.chainreactioncycles.com/kinesis-maxlight-xlt-forks/rp-prod49590 to fit to my old hardtail to use as a winter road bike.
The bike is a marin nail trail with a 100mm marzocchi bomber forks on it. I think the crownrace to axle distance is about 480mm. I know that when the suspension forks sag the 480 will drop to 465-460mm.

My question is would running a fork with a crown race to axle distance of 437mm be okay on this frame?

One inch of fork length is meant to be ~1 degree of head angle so the handling will be a bit twitchy but you won’t die (probably). TBH if you want a road bike you should get a road bike not some bodged up frankenbike.

EDIT: having actually looked at the link it says they’ll work with 100mm suspension frames. This supports the hypothesis you won’t die but it’ll still be an mtb with rigid forks and not a road bike

I use my 20 yr old GT rigid mtb with semi slicks , quicker than my mates hybrids, and a great winter road/ do it all bike.

Why not just buy some rigid mtb forks, and then put some slicks or semi slicks on?

Okay cheers. I know that it would be a bit of a bodge but I can’t afford to get a new bike at the moment so I thought converting a hardtail by putting a new fork on and drop bars would be okay. Plus I can easily fit mudguards. I could get rigid mtb forks but the ones in the link have mudguard mounts.

Please put some pics of your project up once finished.

I use my old Kona for commuting I prefer it to my hybrid. You could get some good second hand rigid forks off ebay or here which would probably be alot cheaper.