2 ways to go about it 1. buy a roller block (and no 351's never had a roller cam except the racing blocks) 2. for small lifter gallery (pre roller 302) block you need whats known as a retrofit kit (comp crane isky etc) it requires you to bore or tap 3 or 4 holes in the lifter valley to install the "spider" (sheetmetal hold down for the roller lifters so they wont rotate) and use of a small base circle cam and special lifters (5l lifters will not work the lifter bores are to short) cost a few hundred bucks.. this on I wouldn't do in the car.. boring holes and tapping them.. ughhh do it at a rebuild or prepare to have the engine cleaned afterwards or run solid roller lifters with linkbars and use the small base circle roller cams(bad idea they flex really bad because they have no "meat" on them) as for "notching" the block it's not the block it's the heads you have to cut slots in them if you want to remove the lifters (8.2 deck blocks 260/289/302/5L) cleveland and 351w blocks do not need this) basically you mill out 8 slots per head to get the lifters to go in while the heads are on or you remove the heads each time you pull the lifters out. I used to work for a engine builder and have studied the 302 in depth for years..
So a 351/late model 302 firing order sounds different from a older 302??... yes the 351w from 69 till present and the roller cammed 302s after 86 have the same firing order 289 302 and all other fords (as far as I can remember) use the 302 firing order.. 5L motors and 351w essentially have the same firing order as chevy/gm/dodge now thats why early 302's have such a wicked idle vrs late model motors nice thing is the firing orders can be changed rewire the dist cap when you swap cams
Lightning 5.8 and '94-later regular 351's were hyd. roller blocks. FYI: Solid rollers don't require ANY block mods. Normally even the pushrods will work. Solid rollers have link bars....so you don't need the dogbones or hold down. Have done lots of solid roller engines and never had to modify one of them. Some had .750" + lift (.469" at the cam). Read above. Never had to modify anthing to drop in a solid roller. You don't have to run a small base circle either....only time you have to go to small base circle is if you have aluminum rods and a long stroke, where the rods & cam interfere with each other. Even then, I doubt a 302 block would allow such a long stroke combined with aluminum rods to happen. The block just isn't big enough. Most solid roller lifters won't come out of the 302 blocks with the heads on, UNLESS the heads were milled on the bottom to let the lifters come up high enough. Victor Jr heads are milled like this, and even then, it's not easy to wiggle them out of there. RPM heads....on a 8.2 deck...even an early block...the lifters wont' come out. Stock iron heads, forget about it. 351w blocks will let you take the lifters out no problem....as the deck is 1.3" taller (1.28 on early 351w's) and same for Clevelands. Taller deck means that the heads are further away from the lifter valley which means the lifters will slide right in/out without interference. early 302 firing order is the same as GM/Slowpar V8s. Cylinders are numbered differently. The late firing order (1-3-7-2-6-5-4-8) does sound a little different, but only to a trained ear. Kind of like telling the difference in a 4-7 swap cam and a standard cam in a SBC or BBChevy. Does sound different but only if you know what to listen for. BTW, did you know firing order can make a power difference? Depending on header design and intake manifold design, it sure can. As to which one is better depends on, again, the intake & headers.
ONLY 302s that were designated "HO" got the W firing order. Non-HO engines in passenger cars and all trucks use the standard order on their roller cams. No block mods needed for solid roller cam. The hydraulic can go either way depending on what brand lifters you use. No base circle changes needed. IMO, the 351/HO firing order sounds different, but it's not enough to keep me from worring about it. The HO firing order actually puts less stress on the crank. I would worry about that alot more than an almost indistinguishable difference in sound. I don't know what order the FE used, but the Cleveland, Windsor, Modified, and Lima engines all use the HO firing order. Although very few 351w engines ever got a roller cam, the blocks were "roller blocks" after 94. Transpose the Chevy cylinder numbers on a 221-302 block and use the GM FO, you get identical FO. Or vise-versa. The HO order is NOT same as GM/Mopar, the old order is. GM guys are now paying big bux to Comp Cams to get what they call 3-7 swap cams... These cams use the HO FO and Comp claims they gain hp just with the FO swap. They also take stress off the crank by swapping the FO. Dave
I read somewhere that the newer chevy LS series motors went to the HO FO. I think I read in an issue of Hotrod.
funny all the fuelie 5ohs had the early 351 firing order.. and they must have made the 351 roller blocks after I stopped working for the engine builder.. as for solid rollers it's been a while since I looked in a 302 with a solid roller I think the heads needed notching to remove them with heads on and I only mentioned the small base circle cams as hydraulics in non roller 302s.. might be wrong now but the factory lifters were to tall for the blocks
Only those designated "HO"... Crown Vics, trucks, SUVs all had regular order. I have some of these non-HO "fuelies"... old 302 FO. My daily driver, 1990 F-150 has a roller EFI with regular FO.
