Maybe 36-38 PSI with the vaccum port off. Play around with it a little bit and see what PSI the car runs the best at. When I bought my 89 the fuel pressure was set at 45 PSI @ 0 vacuum and it ran like ****. Turning it down to 35 PSI made a world of difference. If you can't notice a difference, then just shoot for the middle of the range.
stock ecu, 24lb injectors,bbk ssi intake,70 mm throtlebody..fuelpresure is now set at 40 and car seems to run ok ..engine only has 155 miles on it since we put it in..how many miles should it take to break in... thanks