C4 Dowel Pin Orientation on a '66

'66 200 that I'm mating a C4 out of a 70's mustang to. All the bolt holes line up, but there is only one dowel pin on the driver side that fits into the bellhousing. Is this an issue? I'm afraid without the dowel pins, the tranny won't line up properly based on just the bolts. Am I correct in this thinking and if so, how do I remedy this issue?

You are correct in your thinking. The mounting bolts will not align nothing. You need dowel pins to align the two together.

I only have the one on the driver side, the other side is without it. Do I need a different bellhousing? Everything else lines up perfectly.

Is it that your block dosen't have the other dowel or the place for one that lines up with the bells second dowel hole? If so you might be able to cut one from shoulder of a long bolt or some bar stock.

The is no other dowel hole 180 degrees across. Where it would be is half on the block and half in the space where the starter fits. There is one at the top of the block as well, but the bellhousing doesn't go that high. I think it was for the manual tranny that was on there before.

I would have to see some pictures to know for sure but it sounds like you may need to swap the bell on the C4 to get it to bolt up. That is easy job if you find the right one.

Yeah, thats what I figured too. Unfortunately pics are not possible due to my camera meeting a violent at and a concert recently. Any idea what bellhousing I need?

The C4 came out in 64 am sure on a 65 (Had severial 65's) so would say that a 1964 to about 67 or 8 should work. I would make a patern or take the block plate when you go hunting. The good thing is that the late C4 will bolt right up to that early bell you will need to use that late style torque converter too or change the input shaft to front pump if you use an early T.C.

This is what my block looks like, I borrowed this from another thread and modified it with the arrows. Clockwise from left: red arrow is one of the dowel holes I have, blue arrow is dowel I had to drive out because it didn't line up, pink up top is a hole that I could drive a dowel into but it does not exist, and green is where a theoretic dowel would be 180 degrees from the red. The head scratcher here is the pink arrow. Did a lazy machinist forget to drill it on my block or what? So basically I have just the red arrow dowel and nothing else. I need the later bellhousing that goes higher to reach the two bolt holes and dowel about two inches above the holes I have. Question is, what is the serial number on that one? Curse you and your unnecessary design changes Ford!!

Looks like you have a dual bolt pat. block so you can use the early or later bell. Was no green arrow dowel used at 180 degrees from the red. The 67 and later C4 bells will use the blue arrow and the top dowel pin (no arrow) that shows in your picture. So you need to find a block plate and bell that matches that pattern, would be the best way to go and probably the easiest to find parts because they were used for many more years. Or if you can find one of those early C4 bells and block plate you could pull the pin at top with vise grips and install it at you pink hole position. Need the pictures of what block plate you have and which bell is on your 70 trans to tell if it's for a six or SBF V8?

I have the early bellhousing, thats the problem. The dowel hole shown in that pic with a pink arrow doesn't exist on my block. I stared at it last night for a full 10 minutes trying to burn it in with my eyes to no avail. Apparently the machinist who was supposed to plunge that .375 hole went on break, came back and sent it down the line without it. What an absolute PITA this has become. Does anybody have a serial number or something to help me find one of these '67 or later high mount starter bellhousings online?

Early style C4 bell
1964 170 cid L6
Casting No. (on the bell) C4DP-7976-A
Case Fill, 3-Bolt Starter (Three 5/16" bolts), Top mounted lever assembly

Most common Late style C4 bell
1965 to 1970 170 cid L6 eng. & 1965 to 1977 200Cid.l6 eng.
Casting No. (on the bell) C5GP-7976-A
Case fill trans with 3 bolt starter (5/16)
OEM part number C4TZ-7976-B

Later style C4 bell
Also the Casting No. (on the bell) D8BP-7976-AA will fit by changing starter
1978 to 1981Case Fill, 3-Bolt Starter (One 5/16" & two 3/8" bolts),
OEM part number D8BZ-7976-B
If the boss is cast on the block you could drill it. What casting number is your's and do you have the matching tin block plate?

I believe its the C4DP-7976-A from what I remember, but I'm not at home to confirm it. It would seem the C5DP is what I need, as the later blocks have a low mount starter that will interfere with the headers. I'll see if I can find a pic of one to confirm it. I do have the matching tin plate as well.

Yeah the low mount differant block an 82 up 3.3L is a differant number than those above. If you can find the ones I listed they are are what will work for your block unless you are up to drilling it for your 170 bell. Good luck on the bell hunt.

Alright, thats it, it's time for some madness. I'm gonna drill in the hole that the machinist forgot 45 years ago. I've been looked at crossed-eyed enough times trying to sort out this bellhousing, I'm taking it into my own hands. Here's the plan, feel free to point out a better way if you know one: Take bellhousing off tranny and, using the one dowel pin I already have in the block, orient it and lock it down with the two upper mounting blots. Run a 15/16th's drill through the dowel hole by hand and spin it to mark the center of the hole to be drilled. Use a number 1 or 2 center drill to start a small pilot hole. Use bellhousing to mock up a drilling block, oversizing the 2 bolt holes slightly so it can be moved around to get it on center. Drill 5/16ths dowel hole in drilling block as close to true as I can. Take drilling block and run mounting bolts into back of engine block, leaving loose enough to move drilling block around. Take drill bit and run it through drilling block, moving it around till the tip of it fits dead center into the previoulsy drilled pilot hole; lock down bolts to hold it in place knowing the dowel hole is now centered and perpendicular to the engine block. Drill dowel hole a few thou undersize (in case of drill bit runout) and test dowel pin fit, creeping up on it as not to blow it oversized. Drive dowel pin in and finally finish this sumnabitch up! So. Whaddya think? Drilling block will be made at work on a drill press, so all holes will be perpedicular and true.

Question: How deep should the hole be? Don't wanna go too deep and break through accidentally.

Good plan! Some hand drills have levels built into them to help drill straight. That hole should be the same depth as the other dowel holes in the block or before you pull the dowel pin measure what the amount is sticking out from block and subtract from total length. Roughly guessing think this was about 3/8 to ½ inch deep. Most important is to get the bells center hole matched to the crankshaft center so there is little or no run out otherwise it will wear out the seal and front pump bushing. Good luck

No need for the level, thats what the drilling block is for. I can make it here at work so it'll be perfect. As far as depth goes, I dont have an open hole to check. The two I have are through holes, and the one up top has a dowel rusted into it. Anybody have an open block they can check that depth for me on?

Went to drill as per my plan above, but chaos ensued: the hole I needed to drill DID exist at some point, but was welded over and machined flat, hiding it from my sight. I set it all up and got to drilling, then I felt the drill shift slightly. I pulled the drill block off and saw that the previous hole had opened up after the weld had fallen out. Long story short, back of the block now has a hole that looks like the outside of an "8": original hole with the weld removed and drilled new hole where the bit walked. F**K!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Now what? Also, my bellhousing is numbered C5GP-7976-A. I think the higher mount pattern and dowel are for the manual tranny that was on there originally. Somebody help! I'm at my wits end with this, and I don't want to have to find a new block, as this one is machined and built.

Now what? Also, my bellhousing is numbered C5GP-7976-A. I think the higher mount pattern and dowel are for the manual tranny that was on there originally. Somebody help! I'm at my wits end with this, and I don't want to have to find a new block, as this one is machined and built.

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On the 1965 and up 170 / 200 blocks the higher mount bell pattern and dowels are used, they are the same bell pattern both for 1965 and up manual trans bell or the C4 auto bell.

TucsonHooligan":346pouyx said:

This is what my block looks like, I borrowed this from another thread and modified it with the arrows. Clockwise from left: red arrow is one of the dowel holes I have, blue arrow is dowel I had to drive out because it didn't line up, pink up top is a hole that I could drive a dowel into but it does not exist, and green is where a theoretic dowel would be 180 degrees from the red. The head scratcher here is the pink arrow. Did a lazy machinist forget to drill it on my block or what? So basically I have just the red arrow dowel and nothing else. I need the later bellhousing that goes higher to reach the two bolt holes and dowel about two inches above the holes I have. Question is, what is the serial number on that one? Curse you and your unnecessary design changes Ford!!

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If you have the C5GP-7976-A bell and the correct matching block plate (did you try matching it up with that C5 bell?) these should fit on that highest mounting pattern with out changing anything. You would only need to put back the dowel you removed from (blue arrow) location into the hole it originally was in and use with the unmarked upper dowel that’s there, no dowel in center (pink arrow) and you will be good to go.

Not at all. That bell only fits the lower pattern, its not tall enough and none of the holes line up, not to mention the fact that that would put the torque converter 3 or so inches above center line which wouldn't allow it to bolt to the flexplate.