if you read the gm hightech magazine on an 88 305 tpi fire bird the jet power pulleys dynoed 17 hp and 13 pds of tq dyno proved im picking these pullys up asap wooooooooow does anybody have any info on dyno results from march power pulleys

 

I wouldnt count on getting 17 HP just from the underdrive pulleys. I doubt they will even take .1 off of your ET. However, when I installed them on my car I could notice that the engine reved faster (also did the aluminum driveshaft at the same time) If your charging system isnt at its peak performane now, the pulleys will kill it. Within 1 week of instaling the pulleys I had to get a new alt. and a new battery, now everything seems to be ok. If you do a search on pulleys, there have been many threads with some useful info.

 

You also have to consider how inconsistent chassis dyno's are. I've seen people do back-to-back runs under the same conditions and come up with 10-20hp differences. I saw one guy gain 12rwhp just by loosening the retaining straps 2 clicks. Don't count on the "dyno proven" gains...