351w Roller Block
 

I'm looking for a 351w roller block to drop into my 1977 Bronco. I'm interested in finding one at a local salvage yard for cheap. What vehicles and what year should I look for.

Or is it easier to convert a flat tappet to a roller setup?

I think the mid 90's would be the type you're looking for.

Well if you have a running flat tappet engine in the truck it's easier to convert it to a roller cam since you wouldn't have to pull the engine. But the other side of the coin is the ~$1,000 or so it will cost for the small base circle cam, lifters with the linking bars, new pushrods, etc.

If you're rebuilding the engine anyway get the roller block. IIRC, the blocks were roller ready after 1990 but they didn't start installing factory roller cams until 4-5 years later. The spider, dog bones, and lifters are easy enough to find on eBay if it's a factory roller block with a flat tappet cam.

The 351w wasn't roller ready until 1994(F4TE casting number).. and was found in all F and E series trucks.

Converting an older block to roller isn't really cost effective, the linkbar roller lifters required to run a standard roller cam will cost at least $350, and then you also need pushrods and most cams run $250 or more. You can install the factory roller assembly(spider and dogbones) if the engine is being torn down for a rebuild..the valley has to be drilled and tapped for the spider retainer, but then you have to run a small base circle cam which will cost at least as much as the regular roller and there really isn't much selection. Compare all that to a flat tappet cam and lifter kit which will deliver the same power for as little as $100.

Good luck finding a roller block for cheap, i have been looking for one for my 93 cobra for some time now and cant seem to find one and the few i have found the person knows what they got and jacks the price up

The elusive roller 351W
 

You just have to search constantly and snap up the engine before the next fellow does. I got one for $200 after about a year of searching parted out vehicle ads, not even visiting wreckers. However, scouring junkyards should be successful.

Also look for these engines in 1994-up heavy vans.

Didn't the Cobra 351 have a unique casting number block or head that was otherwise identical to other castings? I seem to have read about that as one fellow in California had to find the correct casting number Cobra part to satisfy the pollution authorities. He was having no luck.

It would be next to impossible for me to find a 351w block out of a 95 cobra R, i was just looking for one to put in my 93 cobra after i pulled and stored my original engine definatly making shure i could put everything back to original when i needed

Non-roller differences? Anything else?
 

It has been a while since a reply was last posted onto this thread so I decided to have a go. I own a 1993 Ford F-250 XL 4x4 with a 351w and a 5 speed ZF. The engine has a quarter of a million miles and is in dire need of a rebuild. I looked near the starter and saw that my block is displaying the F4TE casting number, obviously designating that it could accept a factory roller cam. My question is about my searches for engine rebuilt kits. Should I look for 351w kits for 1994 model years or the 1993 year of the truck. My follow up question to that is would the non F4TE blocks have any other differences other than the valley accommodations for a roller cam lifters, spider tray, and dog bones. Are the cam bearings a different size, other technicalities? I have been trying to find answers for over a year and a half and the amount of technical conversation I am finding makes it seem like the roller 351w in specificity is almost a taboo subject.

No differences for a rebuild kit.. same bearings, gaskets, seals were used for all EFI motors. You should hold off buying anything however until you have a machine shop examine the bottom end and determine what size bearing, pistons and rings it needs... unless you have the tools and knowledge and plan to do all that yourself of course.

Of course, that is my plan. The problem has arisen now because a buddy of mine asked me to tow his c20 and I didn't know it was mountainous. Extremely down on power from fried rings and I have TONS of blow-by. Usual old engine syndrome. I was taking it slow as it was my daily but then I noticed my engine oil was very slightly going up in level and looked almost watery. I did some looking around and the timing chain cover gasket has blown out and it slowly drips coolant into the crankcase. It has 248k miles and the engine has NEVER been apart. Also it has the thicker radiator and the lower radiator hose gently rubs on the power steering high pressure line so it goes through that. I cut up and zip-tied an ice tea can and that prevented it so far. The questions were coming to me as due to the coolant problem, The engine is coming out within the next 8 days so I was simply curious. Thanks!!

Pistons
 

I haven't checked lately, but years ago the pistons and rings for the late 351W engine were much more expensive than the earlier. The difference is that later pistons have thinner ring grooves and rings, but are interchangeable with the earlier wider rings and pistons.

If you have the engine rebored, I would try to find 0.020" oversize pistons rather than the common 0.030", as that will allow your descendants more rebuilds out of the engine. These EFI engines don't wear the bores nearly so much as the old carburated engines.

I went to a junk yard and grabbed a 96 block from an e250, $299 with the whole serpentine system, and all accessories included.

That's the way to do it - you can always scrap or sell the extra parts, but trying to get them one at a time later would be an expensive, tedious process.