Heat transfer is better with no antifreeze but a terrible idea without rust preventatives.
I'm sure there are a few things you could do to improve the cooling ability. Consider that your lower core tubes are probably clogged from sediment and flushing through the hose fittings does not force water through all the rows of tubes. You may need to have the copper brass radiator taken apart by removing the solder on the tanks, dipped to clean, then wire is pushed through each tube to ensure it is clear before resoldering. A few shops like that still exist but it may be a lot cheaper to replace it with a new aluminum radiator that will cool better than the original cleaned.
It is common for the old radiators to have pin holes after cleaning (acid dip) and require a new core between the old tanks. All that stuff is less common and much more expensive now.
I'd put a cheap, modern replacement in and put away the original in storage for the next owner.
A better than original engine driven fan with flexible stainless blades or fan clutch may be available for less noise and more power.
EDIT: I see there are a couple different style hose fittings available. Here is one:
https://www.ebay.com/itm/125405443312?h ... R7aD5qW8YAHere is one guys experience where he adapted a different style than what he had:
https://www.mgexp.com/journal/Charles-D ... get.18407/
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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS
viewtopic.php?f=5&t=13225&p=134742Simple Spring select
viewtopic.php?f=5&t=11815LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12