What size alum rads fit early a's?
Well off the shelf threre is nothing to my knowledge that will fit in the stcok location anymore. You have to modify the core support or go custom.
But on and Early A they are core is 19x17 without the brackets about 2" thick, top tank is old B body style about 4 1/8 wide.
Most all aftermarkets are made for the 67 and up and are 22" wide
Take a look at Rock Auto for a 70 Dart. They list the specs for standard and HD cooling. The HDs are less $$, also what water pump are you using? The early style is on the drivers side, most of these radiators are on the pass side for the lower hose which is the later water pump.
Late model specs like a 70.
17 x 22 x 1 1/4 HD
17 1/4 x 18 5/8 x 1 1/4 non HD
hope this helps some?
