Thanks Espo. Yeah, I had to go back and check everything, but there seems to be a flaw in this kit. My previous build of this kit had front end issues too. Pity I couldn't recall how I fixed that. It was several years ago.
I had a look on YouTube. There's a few videos on there featuring this kit. As far as I can see, they all have the same problem, which made me feel better about mine.
Anyway, the issue seems to be a combination of problems: radiator sits a few mm too high, which has now been trimmed down and the chassis, ahead of the firewall, dips down. This makes the radiator lean forward, pressing against the shroud which I also trimmed back.
But even after these adjustments, it's not perfect. The inner wheel arches hit the firewall and so cannot move back any further. All contact points line up and I know for sure that the body cannot move, as it mounts up platform-style, with locator pins. The main problem, as I see it, is the position of the firewall and the distance between that and the radiator shroud. It's too long.
anyway, I have found a compromise that closes the horrendous gap in front of the windshield. Hopefully get it finished any day now.
test fitted the swamp cooler now it has some BMF strips and a wire support.