I have a '68 360 engine that I need to build. I have been playing around with different options and I have a few questions. First of all, I am wanting to build a hotrod to go into my F100. I have looked into doing a 410 but it sounds as though finding the correct pistons can be a pain unless you special order or shave 390 pistons. Now, if I am going this far why not just make it a 428. Can this be done? Is there enough wall thickness to bore it out that much? Is this feasable or am I confused?

Thanks
Scott

 

Pistons are not that hard (if I remember right you can use the 360 pistons if you use thick head gaskets or use large chambered heads) and you can't bore a 360 the .080 over for 428 unless you get real lucky (not enough meat in the block.

 

Scott you can gap the cyl wall cores through the freeze plugs holes in the block and see. If a 13/64" drill bit shank fits snugly between the cyls you might be able to get the 4.13 bore your after. Natch a sonic map and coreshift permitting. Most 390/360 blocks fit a 17/64" drill bit shank between the cyl wall cores. This is known as the "drill bit test" founded by FordFE.com member Dave Shouweiller aka "Shoe". If you do a search at www.fordfe.com you can read a bit more about it. You can convert the 64"'s to suit your drill bit sizes. That is only the standard measurements used by Dave. Be sure to clean all the crap out from between the cyl wall cores before checking to get an accurate reading. Years of rust and corrosion can buildup inside the block. That's also a good time to clean out all the old coresand and years of crap that might be still inside the block. Freeze plugs are easy to knock out and should be replaced anyway. I use a long 1/2" socket placed on one side of the plug. Than a few good whacks with a hammer to spin the plug toward the inside of the block. Then grab the edge of the plug with plyers or visegrips and yank them out. Be careful not to knock the plug inside the block. If you do they are easy to fish out.....

G.

 

Frost/freeze/soft plug removal? My friends, please consider using a slide hammer. A couple of gentle taps to start the screw head, thread it in, and when you pull they just pop right out every time. I've heard of people using screwdrivers and all kinds of stuff, but a slide hammer works perfectly every time.

 

stock 410 pistons were just a low compression 360 piston from what i gather out of the spec charts...

 

No...

410 pistons are low compression 390 pistons. High compression 390 pistons are 360 pistons. Ther are no high compression 360 pistons.

Just for s***'s and giggles, I just went out to the garage and tested a few blocks. I've got a 352 block, and a couple "mirror 105" blocks, number D3TE. The 352 block, the largest drill I could fit was a 1/4". The two mirror 105's, the largest I could fit was a 13/64". So I do believe looking for a mirror 105 block would be worthwhile. Look in mid '70's pickup trucks.

Remember though, if you take one of these blocks out to .080" over, that block is done. No more overbores after that. Fortunately they're plentiful, around here anyway.

 

Well....if the block can take a 4.13 bore....and has 428 wall cores....good chance it will take the 428 plus sizes. Just my experience but that has been only on 428 blocks. Have you found the mirror 105 castings to be thinner walled than the 428's?

G.

 

I haven't tested an actual 428, so I couldn't tell you. Just from what I've heard the overbored truck blocks dont go any farther after 4.130".

 

I've never had a 105 block so were both in the same boat! Most 428's will fit the same 13/64" bit as your 105 block. On some such as yours they used the same cyl core molds as the 428. Maybe because of coreshift possibly some have not been able to go further. But depending on the amount of coreshift the block should at least go to 4.16. That is the least amount I've been able to overbore a 428 due to badly coreshifted cyl walls. Most can go .040-.060 and live a happy life. But after that .060 it's over. Either way having a few 105 blocks that can go 4.13 has gotta make ya happy!

G.

 

You bet it does! I'd have to say the reason they didn't bore it farther from Ford, is this is a D3TE block, and they weren't building 428's in 1973. If I ever do anything with these blocks, I'll be sure to have them sonic tested.

Edit: The best part: One of those blocks is a $30 360 that I picked up off the side of the path at the junkyard for parts to build my 390!