External and Internal Bypass Fuel Pumps Installation Instructions

These instructions must be read and understood fully before beginning installation. Failure to follow these instructions may result in poor performance, vehicle damage or personal injury. If these instructions are not fully understood, installation should not be attempted. Please consult with BLP Technical Services or a qualified engine builder.
WHICH FUEL PUMP IS BEST - Internal Bypass or Return Line?
In our opinion, it is always best to use a -8 return line when using a belt driven fuel pump. This type fuel pump will handle fuel spikes better than an internal type fuel pump. It also keeps the fuel cooler when using gasoline. Having said that, BLP sells more adjustable, internal by-pass fuel pumps than we do the return line style fuel pumps. The reason for this is they are simple to plumb and easy to adjust. Used for the correct application and maintained properly they are virtually trouble free.
PUMP MOUNTING
In most applications the fuel pump mount bolts to the right hand side (passenger side) of the water pump using the (2) water pump bolts. New water pump bolts and the correct spacers are furnished in the kit. Make sure the bolt hole spot face area on the water pump is flat where the spacers seat. This mount is designed to keep the pump low and compact. With this mount you can use either a 28th or a 32th pulley with the same length belt. Place a protractor on the face of the balancer and make sure the mount is on the same angle as the balancer face.
DRIVE MANDREL S/B CHEVROLET
Make sure the balancer bore is free from burrs and the mandrel will slide in and out easily. Install the mandrel in the balancer using anti-seize in the balancer bore. There is a shoulder on the mandrel and it must seat against the balancer. Install the drive gear and space it to line up with pump pulley using mandrel spacers. The pump pulley is also adjustable in and out. When installing the gear and spacers always use anti-seize. If it is a wet sump engine then the spacing on the mandrel is already set. Use a small amount of Loc-tite on the balancer bolt and torque to 60-65 lbs. If for some reason your application requires a longer or shorter mandrel we can furnish the correct length.

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