I am trying to decide between a gear drive setup or a normal timing chain setup, the motor will never see more than about 6500 rpms...any suggestions either way

i'd go with a true double roller. i've heard the gear drives can cause more drag on the engine. if you see the lucas oil displays in auto parts stores where the gears run through the oil and one is noticeably harder to spin, gear drives are similar to that.

Gear drive will transmit harmonics through the engine.
Double roller is very dependable.

Had a Pete Jackson gear drive in my 468. Took it out and went with a Cloyes True Roller and the difference was night and day. The car will coast after the gear drive was removed.

Before, if I let off the gas in drive, it felt almost like it was gearing down.

Definitely double true roller.

IMO true roller billet gears is a good choice. I have a cheap brother that used a Pro Comp gear drive kit, after the needle bearings fell out and jammed the oil pump and broke the distributor and cam gears he likes the chain now. If you really want a gear drive don't buy cheap here you will regret it.

Purchase the "noisy" Pete Jackson gear drive set up!....You'll dig that "blower whining" sound!.....Just keep in mind, you'll have to use your stock, OEM timing chain cover and if your motor has been line bored, you'll need to order undersize idler gears.:thumbsup:

True roller hands down for me. I've used the cheaper double rollers myself and found they are reliable, but stretch as quickly as a stock chain. I just tore down my 355 that was built in 1994 and the true roller chain is still very tight. I know it wasn't driven much since from 94 until now, but I've had double roller chains stretch quite a bit in the first 500 miles.

Purchase the "noisy" Pete Jackson gear drive set up!....You'll dig that "blower whining" sound!.....Just keep in mind, you'll have to use your stock, OEM timing chain cover and if your motor has been line bored, you'll need to order undersize idler gears.:thumbsup:

I'm curious to why?

I had a PJ in mine and the gears were making an 'ack ack ack' sound at idle that was aggravating.
I also didn't have a TC cover that was OEM. It was a Moroso.

I ask because I've never understood why that sound was happening. It was bothering me so I changed over to the Cloyes.

I'm curious to why?

I had a PJ in mine and the gears were making an 'ack ack ack' sound at idle that was aggravating.
I also didn't have a TC cover that was OEM. It was a Moroso.

I ask because I've never understood why that sound was happening. It was bothering me so I changed over to the Cloyes.


The Pete Jackson gear drives are designed around a stock, shallow OEM timing chain cover, as the cam button rests against the inside of cover to prevent cam walk out....Aftermarket covers are too deep, unless you modify a longer cam button to hold the cam in place.....Unfortunately the "ack ack ack" sound you heard at idle is another characteristic noise of these bad ass gears!.....The noise sort of reminds me of a hammer, striking metal, doesn't it?.....A heavy metal sound for sure!.....I dig the "blower whining" noise and I get alot of people asking me if I'm running a Blower under the hood!:yes:

I have run both the gear drive and a true double roller......For me, the gear drive is out of the picture. The higher quality double roller chains are superior in my opinion.

Gear drive will transmit harmonics through the engine.
Double roller is very dependable.:yes: I saw a case where a gear drive caused a 440 to eat valve springs in a few runs due to harmonics. Bill Jenkins used NYLON timing gears and stock chains in his prostock smallblocks:

" As far as we are concerned there is never any reason to drive the cam with anything other than a stock-type chain. We never use any sort of gear drive. In the past we have been involved in testing and design work with camshaft gear drives. The top quality drives are very well made and they do "tie" the cam and crank together very solidly, as they are supposed to do. We currently feel this may be a bigger liability than advantage. When the crank and cam are joined together by a third gear or pair of gears, every bit of harmonics and vibration developed in the crank will be transferred directly into the camshaft and valvetrain. As it is, we are having trouble holding the valvegear stable, or reasonably so, and using a solid connection to induce more trouble isn't the way to go.

A chain acts as a damper to isolate the valvetrain from all the banging and rattling in the crank, especially the stock chain with an aluminum cam sprocket and nylon drive teeth. Even if there is some slack in the chain and the cam lags a little behind the crank, this can be compensated for when the cam is timed with the crank. However, just to be on the safe side, we don't run a chain to death. They are inexpensive and we inspect the sprockets and replace the chain every time the chain cover comes off during routine engine inspection.

All our Pro Stock engines are fitted with standard Chevrolet Morse pre-'67 silent chain. This chain is wider than the later models. The cam sprocket is a stock pre-'67 aluminum casting with nylon teeth. It is checked for wobble and eccentricity before installation. The center hole is enlarged to accept a Teflon cam bumper, and the bolt holes and drive pin hole are drilled out to accomodate offset index bushings. The Teflon bumper is retained inside the sprocket by a washer that fits under the sprocket bolts. The crank sprocket is not a Chevy gear. All of the stock gears are now made from sintered iron and they will break. We use the sprocket from a Borg-Warner pre-'67 replacement set, as it is made from steel. This setup has never failed or caused one bit of trouble, but the chain must be serviced regularly when used in an engine with very high valve spring pressure."

From "The Chevrolet Racing Engine" by Bill Jenkins, 1976, P109 - 110

There is a big difference in quality of (esp. double roller) chains, and how fast they stretch. No hammering noises for me, thanks! ;)

Good Luck!