Dave - you need to calibrate your hand. Seriously - unless something is really off the intake isn't going to notice +/- 3-4 lb ft difference in torque on the fasteners. I usually just use a ratchet or box wrench and tighten them without leaning on them very hard. As long as they are snug tight with some resistance they should be OK.
You can calibrate your feel a little by torqueing a bolt to 25 lb ft and then put the wrench or ratchet of your choice on it, pay attention to how and where you are holding it and twist until you pick up the slightest movement of the bolt. Then just try to duplicate that same approach and effort on the hard-to-get bolts.
Also - are you sure about the 25 lb ft value on the intake. I thought it was 35 lb ft but maybe my foggy brain cells are remembering a GM BB value. Even with aluminum heads and intake I think I would want around 30 lb ft minimum.
