<a href="https://classicbroncos.com/tech/explorer-5-0-serpentine-accessory-drive-belt-conversion" target="_blank">https://classicbroncos.com/tech/explo...</a><br><br>5.0 versus 302/351 differences. One issue that comes up early in the conversion is the fact that the lower crankshaft pulley on the Explorer 5.0 is integrated with the crank balancer. Although the 302/5.0 small block engines are the same displacement, the thing that is different (other than firing order and a few other details) is the balance. Pre-1981 302s and all 351Ws use a 28 oz. external balance, and 1981-up 5.0s use a 50 oz external balance; this means they use different harmonic balancers and different flywheels. Late model engines can simply bolt on the Explorer balancer because the Explorer engine is a “5.0”. But what do you do if you have an earlier small block, a “302” or a 351? To adapt the Explorer crank pulley/balancer to a 28 oz. engine you can do one of four things: (1) have a machine shop rebalance your existing Explorer balancer, (2) you can go to <a href="http://www.damperdudes.net" target="_blank">www.damperdudes.net</a>, which does an excellent job, and for $115 total will rebuild, rebalance, and ship your balancer in about a weeks time, (3) if you are doing a build on an engine you could have your crankshaft and flywheel re-balanced to 50 oz external balance, or (4) call Randy at <a href="http://www.drivenautoparts.com" target="_blank">www.drivenautoparts.com</a> who has an adapter pulley to bolt on to your existing 28 oz. 3 bolt balancer. His pulley is right at $75 (at this writing) and is a very nice piece.