[bosgencon]

I have a 1989 Ford F350 with a 351 Windsor. I had to replace the long block with a rebuilt one. I re-used most of the original parts with the exception of the distributor and water pump. When I start it it sounds fine, a little bit of a rough idle but not bad. It then seems to surge as if it had a long duration cam. When I tap the throttle it goes away for a minute or so. Any help would be greatly appreciated !!!!!! Also no check engine light on.