I have a D4TE 351W block and it has extra stud bosses cast into the main webbing area. It is very much like the 351C main area(all 351C were cast with extra stud bosses for 4 bolt mains). My question is: Were all 351W blocks cast with the extra stud bosses(not drilled of course) or only some of them? I sort of wonder if Ford had plans on using a 4 bolt mains setup but never went through with it. Can anyone tell me what a "typical" 351W main area is cast like(ei: two stud bosses for the main bolts or four stud bosses, 2 drilled, 2 undrilled)? Any help is appreciated.
The 74 and older blocks have a thicker main web on 2,3,and 4 that is similar to what Ford sells today as their Sportsman block. They are getting harder to find but some are still out there and people still look for them. I always wondered if Ford didn't dust off those old pre 74 core molds and sell them as Sportsmans. Yes those blocks can be fit for 4 bolt caps. Milodon used to sell caps - maybe still do. I think they used a short 7/16 bolt (only goes into the block about 1"). In my opinion, if you want a 4 bolt main 351 it may be questionable if you should convert one of these blocks or just go shopping for a SVO block -- unless you can get good deals on machine work and a set of caps. Your D4 block in 2 bolt fashion with a main cap girdle should really be able to take some abuse. Cleaver
I believe the '69-'81ish blocks were all about the same in the main webbing. Later on when they received a 1 piece rear seal, they changed the webbing to a thinner web (less weight) but they still will hold about as much power as you'd want to put to it. Oh, and don't worry about putting 4 bolt main caps on it, it just weakens the webbing. Stock 2 bolt caps are strong enough to accomodate about 700 HP (early blocks).
Focus on aftermarket rod bolts! That is the weak point on most Ford engines. If you keep the stock rods, just polish the beams. Balancing always helps bottom end strength too. Main studs are a good route for the caps. Resizing the mains and rods is a good idea as well. Keep the harmonics down and use quality fasteners and your engine will be very strong. Good luck Dave
I tried to post pics over the weekend. Unfortunately, my pics were too large. I will try to shrink the size and re-post them. When I post pics, I will provide 351C and my D4TE 351W main saddles with the stud bosses.
Cleaver has a good point, time and cost of machining for four bolt can be offset by just using your two bolt setup and a good cap girdle. They run from 100 to 300 and will give you added strength in that area. Most come with ARP studs and nuts also.
Old Guy as always you be da man! 69 and most 70's 351W blocks have whats called a "flat rail" across where the caps sit. These are better for putting the program 4 bolt main caps into, because they are a little easier to machine. All the 351W experts I've ever talked to say that these block are the stongest of all the factory blocks because of the higher nickel that was put into making the blocks for those years. I have ran a 69, a 74 and now another 74 block and I couldn't tell you the difference. I have used only main studs in some of my motors but now I'm using a main stud, girdle, windage tray combo from Canton. If you can afford it use the program caps and have your block machined for the 4 bolt mains, it's stronger then a girdle. I used only ARP main studs on my first 408W and had very little cap walk shifting at 6,400 As always just my .02 Bossmav
http://mmb.maverick.to/showthread.php?t=21706&highlight=351w+block+strength Doesn't matter if it's got 2 bolts in the caps or 4...same thing happens every time. If you take a good hard look at the main webs and cap registers, there is VERY little material to install the outer bolts. Small Block Chevy's are similar...so thin and so little material, that they tend to be stronger with 2 bolts vs. 4. Then you figure in the cost of the caps, align boring and all the required work to get it all "done up" and you're looking at the price of a good used aftermarket block.
