Big Block Ford - All 429/460 V8s and all 352/390/406/410/427/428 FE V8s
429-460 V8- These engines have used a number of different timing pointer locations. Most engines have the pointer at the "10 o'clock" position looking at the front of the engine. The Professional Products damper has two keyways, a 1/4" and a 3/16"keyway. Using the 1/4" keyway will correctly position the damper on a production crank (or custom crank machined to factory production specifications) allowing the "10 o'clock" pointer to line up with the 0° top dead center mark on the damper. Use the 3/16" keyway with Ford Racing M6303-A600 and B600 crankshafts or on a M-6011-A600 orB600 short block kit. The "10 o'clock" pointer should align with the 0° top dead center mark on the damper.
Note: When using this damper with a Ford M-6303-A600/B600 crank, use a Ford Racing spacer M-6359-C460 over the crank snout before installing the damper. This spacer is used with internally balanced engines only. The stock spacer is Ford part number M-6359-D460 which is used with stock cranks. This damper has the stock four bolt pulley pattern and also the BB Chevy three bolt pattern which allows use of most crank trigger ignition systems or other aftermarket pulley combinations designed for BB Chevy.Adjust pulley alignment by machining the crank spacer as required.
FE V8- These dampers are all neutral balance (no counterweight) although the 428 does use a counterweight on the flexplate, so technically that engine is an externally balanced model. Our FE damper is a duplicate of the stock 427 high performance damper. It is 7.5" in diameter while all other FE dampers are 7" in diameter. Our 7.5" diameter damper can be used on all FE engines. We supply a new timing pointer for the larger diameter. Our timing pointer will fit both early and late FE engines. If your engine uses one v-belt pulley this damper can be used as is. If your engine uses more than one v-belt pulley, unbolt the supplied pulley, and using our supplied aluminum adapter spacer, bolt your stock pulleys in place using the stock bolts. These dampers have both early and late pulley bolt patterns tapped in them so all the stock pulleys will fit.
Small Block Chrysler V8 Engines - All 273, 318, 340 and 360 cid V8s including Magnum.
How to Determine Which Counterweight to use:
1. All internally balanced 1967 and later 318 V8 standard and Magnum, all internally balanced 273 and 340 engines with forged cranks: Do not use any of the counterweights for these applications.
2. 340 externally balanced 1972-’73 engines with cast crank. Use counterweight#91014. (Pt. No. is stamped on weight.)
3. 360 externally balanced 1993-’97 engines with cast crank. Use counterweight#91013. (Pt. No. is stamped on weight.)
4. 360 externally balanced 1971-’92 engines with cast crank. Use counterweight#91012. (Pt. No. is stamped on weight.)
Installing the Counterweight - Included with your damper is a small tube of thread sealant. Coat the threads of the two supplied socket head capscrews and attach the counterweight to the back side of the damper into the two appropriate tapped holes. With bolts still loose, push counterweight to the outside of the damper so that the outer radius of the counterweight is touching the inside diameter of the damper. This is important. Tighten the two bolts to 8-9 lb. ft. of torque.
Neutral Balance Engines- Neutral balance means the same as internally balanced. An externally balanced engine has a counterweight on the harmonic damper and a matching weight on the flywheel or flexplate. Internally balanced engines have no offset weight on the damper or flywheel/flexplate.
Some engine builders convert externally balanced engines to internally balanced by adding Mallory metal to the crank counterweights which eliminates the need for the counterweights on the damper or flexplate/flywheel. If you want to do this with your engine, simply use our balancer without any of the bolt-in weights.
1. Loctite is recommended for securing the bolts holding the accessory pulley to the damper.
2. Before starting the engine, make sure that there is no interference between the damper and any part of the engine. This includes the water pump, timing cover, timing pointer, or any other part of the vehicle.
3. Early models had one pulley hole offset. Drill hole out oversize to line up with tapped hole in damper. Or elongate hole with file.
Big Block Chrysler V8 Engines - All 351, 361, 383, 400, 413, 426, 440 including 426 Hemi. (Will not fit early Hemi)
How to Determine Which Counterweight to use:
1. 1972-'78 383 & 400, '71 383 2-bbl and '74-'78 440. (Cast crank engines only.) Use counterweight #91015. (Pt. No. is stamped on weight.) If you're not sure if your engine has a cast crank with an externally balanced damper, examine your old damper and see if it has a portion of the back of the damper that is carved out. In other words, it will have an area where there is less weight than on the rest of the damper. This means it is externally balanced.
2. 1970-'71 440 6-bbl and the 1971 High Performance 440. Use counterweight#91016. (Pt. No. is stamped on weight.)
3. All other Chrysler big blocks require no weight.
Installing the Counterweight- Included with your damper is a small tube of thread sealant. Coat the threads of the two supplied socket head attach the counterweight to the back side of the damper into the two appropriate tapped holes. With bolts still loose, push counterweight to the outside of the damper so that the outer radius of the counterweight is touching the inside diameter of the damper. This is important. Tighten the two bolts to 8-9 lb. ft. of torque.
Neutral Balance Engines- Neutral balance means the same as internallly balanced. An externally balanced engine has a counterweight on the harmonic damper and a matching weight on the flywheel or flexplate. Internally balanced engines have no offset weight on the damper or flywheel/flexplate. If you, or your engine builder, want to convert an externally balanced engine to internal by adding weight to the crank, simply use our balancer without any of the bolt-in weights.
1. 426 Street Hemi and 426 Race Hemi use different TDC marks than all other big block Chrysler engines. Our damper has these TDC marks indicated on it. MSD offers a stick-on timing tape assortment (MSD #8985) that you can use if desired. There are several size tapes in the MSD assortment. Select the tape for use on a 7.25" diameter damper.
2. Early models had one pulley hole offset. Drill hole out oversize in order to line up with tapped hole in damper. Or elongate hole with file.
Special Note: To use this damper on a 426 Hemi requires our pulley spacer#80013 in order for the v-belts to line up correctly.
Pontiac V8 Engines - All 1961 - '79 engines - 326, 350, 389, 400, 421, 428, 455
Note that in order for this damper to fit '61 to '68 engines, you must use a '69or later model timing chain cover, water pump, pulleys and related components.
These parts are available from a wrecking yard or from Year One at800-932-7663. (www.yearone.com). Kauffman Racing Equipment (www.MR-1.com) makes a very nice '69 and later front aluminum timing cover that is very reasonably priced. A similar cover is available from Performance Years.(performanceyears.com) These dampers, unlike some competitive models, have the original Pontiac accessory pulley bolt pattern on them so that your original stock pulleys can be used if so desired. The Pontiac damper is a neutral balance model and essentially the same damper was used on all the various size Pontiac engines manufactured from 1961 through 1979. This damper also incorporates a big block Chevy accessory pulley bolt pattern as well as the stock Pontiac accessory pulley bolt pattern. Some modification tithe pulley or damper hub will be required to use BB Chevy pulleys.
Olds V8 Engines - 350, 400, 403, 425, 455
The Olds harmonic damper fits a wide range of Oldsmobile engines. It is an externally balanced damper with a bolt-in counterweight. As with all of our dampers, if you elect to convert your crank to an internally balanced engine, you can use this damper simply by removing the counterweight. Our Olds damper is dimensionally identical to the stock OEM model except it is made of superior material, has a bolt-in counterweight...which can be removed for a neutral balanced assembly...and also has the stock accessory pulley bolt patterns well as a big block Chevy bolt pattern. The Olds bolt pattern is four5/16-18 tapped holes while the big block Chevy bolt pattern is three 3/8-16tapped holes.
Chevrolet V8 Engines - Small Block and Big Block V8s (Except late LT-1, LS-1 and LS-6. See supplemental instructions)
Our Chevrolet dampers for both small and big block are available in internally and externally balanced models. The basic damper is the same, the difference is the addition of the bolt-in counterweight. If you have an internally balanced model and decide to put it on an externally balanced engine, you can bolt in the proper counterweight (which is also sold separately). Conversely, you can convert an externally balanced damper to internal by removing the weight. Our 6-3/4" S.B. Chevy 350 (#80000 and #90000) and 400 dampers(#80001 and #90001) are too small to incorporate a bolt-in counterweight so they cannot be modified in this manner. While the #80010 damper is suitable for racing applications, it is not an SFI spec damper.
Note:Small block Chevys have used three different TDC timing tab pointer locations. If yours doesn't line up, any of the aftermarket bolt-on timing tabs will provide the correct pointer positioning. See note on first page. We have made a running change in our 6-3/4" SB Chevy 350 dampers #80000 and#90000 by adding another TDC mark which is labeled "Vertical TDC." This is for those engines produced from 1984 to 1995 which have the TDC mark at the top of the balancer and are timed by looking down behind the water pump to view the timing pointer. Use an aftermarket timing tape if desired.
Notes on Balancing
We take pride in the quality and accuracy of the balancing of our dampers. Not only the overall balance, but the accuracy of both the weight and positioning of our counterweights on externally balanced models. We frequently get calls from engine builders and balance shops complimenting us on providing the most accurately balanced dampers they have seen. If you are building a new engine from scratch, and it is a neutral balanced engine (no counterweights on the damper or flywheel) your balance shop can balance your engine without the damper. If it is an externally balanced engine, the balance shop will need both the damper and the flexplate or flywheel to properly balance your engine. There is no need to rebalance a Professional Products balancer.
If you are installing the damper onto an existing engine. and the engine was correctly balanced, your engine will still be properly balanced.
Unfortunately, many of the aftermarket externally balanced dampers being sold today, do not have the counterweight properly positioned nor is the weight of it correct. If you have an existing engine that was balanced with one of these dampers, it is possible that switching to our damper, which is correct, could show up as a problem. Most balance shops will not balance an assembly with these sub-standard aftermarket dampers, so the chances of you having a balanced assembly with one of these dampers is slim. If you do install our damper and have shake or vibration, you will need to rebalance the engine.