Hi Ford gurus,
I have a '91 F-150 with 5.0. It's time to think about engine rebuilding. Easiest for me would be to build one, and swap it in. So....

When I see a block for sale that's for a 302 "roller," that's referring to how the valve lifters work, right? What is the actual difference? What parts from my stock 302 can I re-use? Same heads? Is there any advantage/disadvantage to a roller engine? Is there any difference other than the heads and cam itself?

Sorry for the basic level questions, but I can't find this info.

Thanks,
Chuck

 

the only difference between a roller and non roller motor is the cam and lifters. the roller are just that lifters with little rollers on the bottom, this allows the lifter to move over the cam lobes with ease. were as, a flat tappet or non roller has a flat bottom and moves over the cam with more friction. The plus sides of the roller is the cam can be more aggressive yet retain a better idle quality. Roller is the way to go but don't lose any sleep if you have to stick with a flat tappet or non roller block. First thing you might consider is getting a 351 or 5.8 motor as it will bolt right in and replace your 302 without any major problems. You would be able to use all of your efi equipment and with minor changes it will work there are a couple of people on here that have actually done this so right off the bat you would gain 49 cubic inches, not bad huh? Keep asking questions and these fellows with have you educated in no time flat. Later

 

the 302 intake will not work on the 351W, you will have to change intakes, and your exhaust y pipe. DW

 

Thanks!
I'm getting more enlightened every day here.
Chuck

 

yeah should have mentioned you would need a 5.8 (351) lower intake (minor changes) , your upper can still be reused, but other than that your good, with a little rewiring of the injector harness or chip. later

 

The fuel rail assembly has to be modified as well since the 351 is wider.

I'm not sure about all of the modifications required for a truck, but doing a 351W swap is not quite as easy as it seems. You need exhaust modifications, a new intake, revised fuel rails, a 28.2 oz balancer, and a matching 28.2 oz flywheel or flexplate. If you get a junk yard motor, you can probably use the balancer and flex plate that it comes with, however you wouldn't in a high performance application. 351W's generate more heat, so in many cases you need to consider a new radiator, though I'm not sure about in a truck. The distributor is different on a 351W from a 302 - it has a larger diameter oil pump drive shaft, so you will need a new distributor. You will also need new accessory drive belts, which is a minor expense, but these little things add up. In some cases you may require special brackets to properly mount your accessories since the distance between the heads and the front cover is greater on a 351W than on a 302. For a Mustang application, you also need a new oil pan and taller hood, but this is probably not a concern in a truck application.

If you are using a fully stock 351W setup out of another truck, and get the complete engine - pan to intake, balancer to flex plate, and the distributor, this swap is probably fairly easy. If you decide to hop up the engine, or only got a short block, there are a lot of little odds and ends to consider on this swap.

I did this swap in a '90 Mustang and in that case I had to change virtually everything except the motor mounts. This even included the PCV system since the Victor 5.8 manifold and 5.0 Mustang valve covers I used do not make provision for PCV.

Good luck.

-Matthew