kilrb

I'm going to be undertaking my head/cam swap here soon, and I have heard from some that re-using the stock pulley can be a bear, and that an under drive pulley will not only net a few more horsepower, but be easier to install. Is there any truth in this? Is the only reason to install one the added hp?

C5 Corvette

my stock balancer seperated itself at 100k and was rubbing against the front cover and causing the main belt to hang on for dear life. If yours has a good amount of miles on it I'd get a UD pulley. if not you're probably safe with the stock one. Also the first UD pulley I bought was off balance and we noticed after installing it so had to do that again. Make sure you go for a great brand and do it right once

jordanfd

If you are going to do H/C for more power then by all means do the underdrive pulley at the same time. Why not????? You already have the old one off. Do it now are be sorry later. Frank

ICaughtVetteFever

willyfastz

If you do reuse the stocker make sure it doesn't have a grove in it were the seal fits around it.

SLPRC5

I say go with the UD pulley as I did and many others did. Use a new crank bolt and red loctite.

2klude

94legaleagle

Put on an Underdrive pulley, and get a ARP crank bolt and torque it to spec - do NOT reuse the original crank pulley bolt!!

94legaleagle

I'm just finishing up a h/c install, and I put on an ASP underdrive pulley - I was somewhat worried about getting the pulley seated and torqued to spec after reading some of the stories here on the Forum - I used the ARP crank bolt and had NO problems getting it torqued down - I think the KEY to achieving proper torque is to have a big enough ie: long handled Torque wrench - I used a 1/2 inch Snap On Torque wrench w/ about a 18 inch handle and I had NO problems!!

jeanlucpicard

I replaced mine with a new OEM pulley and front engine seal. After all the work to clear a path to change out the cam this is a simple task and well worth the $200 in parts while you are in there. I opted to run the OEM since I installed a double chain Rollmaster timing chain and they have a history of clearance issues with under drive pulleys.

kilrb

I have about 55k miles on the Vette. I don't know if that makes it a no-brainer or not. I have about $4k tied up in the project so far, and I wasn't looking to add to it unless it was necessary. I'll definitely use an UD pulley if I don't re-use the stock one. Thanks for the responses...

Z06ufgrad2002

If you reuse the stock pulley I would strongly recommend you pin the crank. Won't cost you much to do that and adds a ton of insurance to prevent the pulley from spinning on the crank. The OE pulley has a tendency to stretch during the original install. After removing it and reinstalling; it may not grab the crank as well as the firtst time it was installed. The pin will aleviate that potential all together.

vetred

If after all the $$$$$$$$$$$ you spend you find yourself with enough to put the underdrive pully on ,....well...... yaaaa!

Ikester

happa

OK Im a little worried now. Just finished my cam install 3 days ago and used the my stock pully. It was replaced about a year ago or roughly 5k miles. It being almost new what are the odds of it slippin?

willyfastz

Shouldn't if you used a new crank bolt and it stays tight. Maybe reach down there and check the bolt a few times for the first few weeks.

jeanlucpicard

Probably pretty small. A couple of items to consider when reusing the pulley -

1. The 2 pieces separate and scatter across your radiator and hood, etc doing a lot of damage.
2. The front seal does not seat to teh new pulley shaft due to previous seal cutting a shallow groove and now you have an irritating oil dribble.

Really, that's about it. When I did my H/C upgrade I replaced all the hydraulic lifters, cups, sensors, pulley, gaskets, seals, sensors, water pump, oil pump, timing chain (went to Rollmaster double), hoses, etc - just about rebuilt the engine.

When you are in for about $3K for a H/C what's another $1,500 or so to make sure everything is in top condition? Beats being left in BF nowhere with no cell phone signal - like my column lock did to me in Arizona!

Time will tell but I would just enjoy the car and not worry about it for now.

kilrb

It's not like I can't afford it, man... I just didn't plan on buying one if it wasn't necessary.

vettenuts

I would change it, even it stock. They are a pain to change later and the damper will be even more important now with a cam to maintain its primary function on crankshaft harmonics. You will also likely rev higher with the new cam so another important reason. Don't use a bolt to pull it on, you will be asking for problems. You need to make a puller, very easy and will save a lot of grief.

kilrb

I have heard a lot of talk about the brand counting as far as balance... Can you give me a reccomendation of whose pulley to buy?