Hi, I have a Mk1 van that has a 1600 fitted with a 1300 radiator and when its warmer it gets a bit hot. I need to change it but don't know what to. I want to keep a old school look so no alloy radiators. The 1600 will be a warmed up GT spec engine and need a radiator that will cope.

I`d go with a 2 litre radiator if you can find one and then try to work out some hoses for it. Should give you plenty of cooling

If you can find a Cortina mk2 radiator go with that , it bolts in directly and has a large top tank. . Also looks trick! I had one in my mk2 for many yrs and high powered pinto's without a problem , also fit a thermo fan if not done already. .
Cheers

I was going to say i think there's a Cortina rad which is the one to get (wasn't sure of the model).. Marty beat me too it! 

Just be careful with the old cortina and escort twin cam radiators. Yes they have big tanks but very low FPI (fins per inch) which plays a big part in cooling efficiency

So I need a Mk2 Cortina radiator with a fine core. 

I think they're all low FPI as standard so I'd be looking for a recored one. Or cut & weld the box section underneath to fit a 2L rad but I really don't think that would be necessary. Have you had your 1300 rad cleaned out? I ran one with a 1600 in Qld for a couple of years with no overheating.

No I haven't had it cleaned, it is a coarse core.

Could also consider a mk2 escort ghia one which I believe has more cooling fins but some loss of capacity due to transmission cooler in bottom tank.
If you are running the standard engine fan is there a shroud fitted?
SFE

At the moment a engine fan but that will change later. Is there any issues with the bonnet line on a Mk1.