down pipe bolt

ok, changen the head gasket in my 89 civic dx 1.5, anybody know off the top of their head what the size of the bolts at the downpipe are?? is it just a shitload of rust i need to pound out of the way and make a 12 or 13 fit? thanks in advance
Doug

Downpipe or header? The header piece where it mounts to the head are 12mm (on mine anyways) and the bolts that attach to the down pipe are 14mm... PB Blaster works wonders!

i got the 12's off at the manifold... i need down by the collector, which you say is 14, thanks