Underdrive Pulley a MUST HAVE for HOs

[Nathan in MI]

if you dont have A/C or a smog pump anymore you could get the march pulleys I got for my 351. I'll have to grab a part # when I go back home, was only $45 for the crank and $35 for the water pump pulley, I used the stock alt pulley and no PS pump for now. Everything lines up just fine.

*ahem*

I 86ed my A/C and smog pump, so I'd be interested in this as it sounds significantly cheaper than the ASP underdrive at $150+shipping.

[1987cp]

*ahem*

I 86ed my A/C and smog pump, so I'd be interested in this as it sounds significantly cheaper than the ASP underdrive at $150+shipping.

Me three!

Mercmarquis, you're running a manual steering box, or what?

[monterey1962]

I've been curious about how this under-drive pulley would effect a lopo 302, so I put one on the '91 GM today. I put seven miles in-town on the car with the pulley on and there is a slight noticeable difference. Mostly, the engine seems to be a little quicker to react to the gas pedal and the car is a little jumpier in first gear. Keep in mind, my '91 is bone stock, through and through. I'll be watching to see if it effects anything like in-town mpg's and such.

I used belt #K060490 and it fit perfectly without issue. However, the '91 has a 100amp alt, so I don't know if the pulley is larger or smaller than that of a 65amp or 130amp alt. I'm not running a belt to my A/C at this time since the system is dead.

I will be putting my other under-drive pulley on S.U. in the following weeks. I'm sure it will make a big difference on her since she runs much higher rpm's when playing.

[Grand Marquis GT]

Jesus christ, that's a big difference!

[monterey1962]

I have edited my previous post. I had the timing set way off at the time of the original test drive. Now that the timing is set properly, the car's behavior has improved.

[DuceAnAHalf]

I have one of those tiny pullies also, however it needs to be spaced out about 1/8" for proper belt alignment

[gadget73]

I figured the 5060490 would be a better fit. I have a 5060485 on my car and its really damn tight. Unfortunately it was the closest thing anyone had in stock, so I used it.

[Blaze86Vic]

The coolest part about it, is that the accessories don't overpower the exhaust note anymore.

[88Vic]

That's what I used to think was wrong with my truck, I thought the accessories were just too loud for my liking, but I figured out the alternator bearings are going bad so I either need to rebuild it or buy a new one, and since rebuilding seems kinda impractical i'll save up for a new one.

[P72Ford]

Wow, thats a significant difference in diameters... didn't think they were that different.

I'll be interested to see how this affects MPG's, if at all. The pulley is just 4 bolts right? It doesn't require a slide hammer to pull it off?

[monterey1962]

Wow, thats a significant difference in diameters... didn't think they were that different.

I'll be interested to see how this affects MPG's, if at all. The pulley is just 4 bolts right? It doesn't require a slide hammer to pull it off?

Yes, just four bolts and it falls right off the crank. Took about 15 minutes to do, but I was poking around under the car looking for leaks.

[gadget73]

yeah, 4 bolts. If it doesnt fall off, just whack it with the handle of the ratchet and it'll probably come right off.

[Blaze86Vic]

I rebuilt my alternator, I did a write up on it too.

http://www.grandmarq.net/vb/showpost.php?p=188896&postcount=51

[monterey1962]

Well, after a few weeks of running the under-drive pulley on a lopo, I've discovered a 1mpg loss. Drove the car the same as I always have. I'll probably put the stock pulley back on this weekend and see if the change is actually related to the pulley or something else. It should be noted that, I found absolutely no benefit of running this pulley on a stock lopo. I would suggest saving your $160 for the pulley until you actually modify the engine.

[turbo2256b]

Well, after a few weeks of running the under-drive pulley on a lopo, I've discovered a 1mpg loss. Drove the car the same as I always have. I'll probably put the stock pulley back on this weekend and see if the change is actually related to the pulley or something else. It should be noted that, I found absolutely no benefit of running this pulley on a stock lopo. I would suggest saving your $160 for the pulley until you actually modify the engine.

Shouldnt think there would be much differance in economy. Engine is still running the same RPMs at speed as before. Just the fead spinning a bit slower.