Hello everyone, First, I have to say, hats off to all of you for being so willing giving your to time to provide advice. I'm new to the site and this is exactly what I was looking for. I've owned my F250 for 11 years. It's tired and needs a rebuild. Some 6 years ago, I tackled the C-6 and vow to never crack that task again. My wife feels she still smells tranny oil in the house.
My question, The 352 is aready 60 over. Do I find another 360 block and start there and if I can remember, isn't there different bolt patterns on C-6's. What is what. 8 or 9 bolts to hook to the engine. Thank you for any info. this is going to be a great winter. I looking to build a solid hi pro motor. Your advice is greatly appreciated.

Sincerely,

LDH

 

I can't help you on the tranny bolt pattern question. I've never heard that the C6 housing had different patterns, but I guess it's possible.

As for the motor, my guess is that you need to find a new block. Generally accepted wisdom is that pre-75 FE blocks generally won't safely take more than a .060 overbore. Those who know say that some will safely go to .080 over, though you won't know until you have it disassembled and checked out by a good shop. Supposedly, the "reverse 105" 75 and 76 blocks are much more likely to safely take .080 over.

My recent experience, though, is that good used 360 motors are a dime a dozen (o.k., more like $100-200). If your 352 is still running, my advice would be to leave it in the truck for now, buy a decent 360 that's stock or not more than .030 over already, and rebuild it outside the truck. Once the rebuild is done, just swap the motors and toss the 352 block. You get to keep driving your truck in the interim.

Better yet, rebuild that 360 as a 390 or 410 stroker. It'll cost you a few hundred more bucks because you'll need to replace the crank and rods that came in the 360, but it's money well spent in terms of the power you'll get.

karlsd a/k/a "ksd"
69 F100 Explorer 360/C6

 

Who put the 352 in your '68 (if you are bored 060 over then you actually have a greater CID than a 360)? Just curious because that is an uncommon swap since the truck came with either a 360 or 390 from the factory (if it originally had a V8).

Anyway, Karl has some good advice. Since the FE's are still fairly common and cheap to acquire, I'd find a core somewhere and rebuild it...make sure it is at least a 390. There is not any obvious characteristics that differentiate the majority of FE's so you'll have to either measure bore and stroke or pull the oil pan and check casting numbers on the crank. One little trick that everyone seems to agree on is to check the crankshaft flange. The 390 has square notch in crank and 360 has semi-circle notch in crank.

Don't worry about the tranny, yours will bolt up to any FE block.

 

Good point. The 352 wasn't used after 68, as it was replaced by the 360 after 1967.

My suggestion to buy a 360 is because they are plentiful and cheap where I am (Memphis). I looked for several months for a 390, only found one, and the asking price was $800. I could have had 8-10 360's for that price. Since the crank and rods are all you need to turn a 360 into a 390 or 410, and you can get a 390 or 428 (to make a 410) crank and rods for about $200-300, my decision was to rebuild a 360 as a 410.

karlsd a/k/a "ksd"
69 F100 Explorer 360/C6