SNIP " I am putting an 86 360 in my 73 Commando. When I sold " the original 304 out of the Commando, I did not have " time to keep the 3 hole balancer that came on it. " " So, will the flywheel that came off the 304 with the " three bolt balancer be balanced OK with the 360 4 bolt " balancer? no. SNIP AMC V8 engines are externally balanced and depend on the fly wheel or flex plate matched to the displacement of the engine and in some cases the application as to what transmission it will be mated to along with the harmonic balancer (Damper). With the exception of the previously pointed out '70 360/390 application each engine size will have its own unique flywheel and harmonic balancer (damper) applications. SNIP " If it is just a matter of comparing part numbers, what " is the proper part number for a 360 flywheel that will " work with the 4 hole balancer? '70-1 360 p/n 3196929 '72-? 360 p/n 3212653 - i believe this fits all post-'72. SNIP Here is additional information that may prove useful. New Harmonic Balancers (DAMPER) Part # 910 4501E 1970 390 cid and 1970-1972 360 cid Part # 910 4501B 1970-1972 304 cid Part # 910 4501G 1968 and 1969 390 cid All includes a new woodruff key and are 3 bolt pulley types Available from Kennedy American, American Parts Depot and Galvin Rambler. There may be others also so check with an AMC parts vendor. Harmonic Balancer (Damper) Part # from 1981/82 Parts Fische 3 Hole Damper from '81 Parts Fische 323 0130 V8 304 323 0131 V8 360 If you do a Yahoo search with the following information; Damper 3230131 Additional web sites will come up that may prove helpful Also Group 1.056 FLYWHEEL ASSEMBLY, Crankshaft (Manual Transmission) Part # Application 317 9069 '66-69 290 318 1609 '67-69 343 319 1662 '68-69 390 319 6927 '70-71 304 319 6929 '70-71 360; '70 390 321 0496 '71 401 321 2651 '72-78 304 321 2653 '72-74 360 321 2655 '72-74 401 323 3955 '79 304 323 6523 '81 304 321 2653 '81 360 321 6524 '82 V8 (304?) In addition if you do a Yahoo search using the following information; FlyWheel "321 2653" Additional sites on flywheels will come up. Hope this helps somewhat. As far as I know on a given displacement the 3 or 4 hole damper is unique to the pulley configuration used only, if you have the need for one or the other you can purchase or find the appropriate number of holes for a pulley from the same displacement engine. As far as I know despite nuances in OEM fly wheel part numbers that may be seen from year to year you can swap any same displacement fly wheel from engine to engine with out a functional problem. The same goes for harmonic balancers (Dampers). John _______________________________________________ AMC-List mailing list AMC-List@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list or go to http://www.amc-list.com