Well, here's another quick question for you wrenching gurus! What size micrometer will I need to measure the cylinder walls of my 455? Also, 70 heads will bolt right onto a 72 block w/ no mods, right? Thanks, guys! Shawn P. Boden
As a former machinist, I feel as if I can answer your question. You don't measure a cylinder with a micrometer, you would use a hole guage and measure that with a micrometer. Unless you are experienced with taking precision measurements, this job is best left to the professionals. You can be off by a couple thousandths here just by feel, and that's too much when you want an exact measurement.:bglasses:
Yeah, I know you have to use a telescoping guage. I was just wondering if a 0" to 6" micrometer would work to measure the tele-guage. I've measured quite a few lawnmower engine cylinder walls, but never a 455. Just curious. Thanks!
I'm no guru. I AM a Novice. The standard bore size of a 455 is a little larger than 4 and1/4. You would be looking for a bore gage. They are kind of pricey --- better to have a machine shop do it. Nothing complicated about, just cheeper. And yes 70 heads will bolt on to a stock 72 block -- no mods. Good upgrade for compression. It is the 75-6 stuff that requires a special head gasket to work with the 74 and under .
Are you sure it's a 0-6" mic or a 5-6"? It will work as long as it goes down to 4" but I'm sure you already know that. Cylinders are hard to measure, when you have to consider taper and out of round. If there is a ridge at the top, it's better to just have it bored and new pistons fitted. It will last much longer. If it's half used up it's half worn out before you even fire it up for the first time.uzzled:
Are you refering to a 0"-6" dial caliper? Thats not going to be accurate at all when trying to measure a Cylinder. the proper way is by using an inside mic, measuring that with a mic. And this is definatly best left to the pros. it is very difficult to measure to .001. What shop did you work at Joe??
I think he's talking about a kit that has a 0-1'' micrometer; and 6 changable anvils 0-1''/1-2''/2-3'' etc. My experience measuring bores with "snap gages" & outside micrometers has been maddening and inconsistent. Better would be a dial bore gage! = $100-750 Best would be a "borematic"(3 prongs) gage! = $3000-6500 Just my 2 cents. Steve Walsh
After working as a mechanic for a while, I got sick of it and went to school for machining. Ran a lathe for a stainless steel fitting manufacturing company. Semi-precision work, but I the experience did me some good. Got out of that and now I have my own small engine business. I could never use the small lathe I have in my shop if I didn't have machining experience. That thing's worth its weight in gold. And it's pretty heavy!:grin:
Head interchange 70 heads originally came on a "single scallop" block they will fit on a 72 block if you use the proper head gasket.The double scallop block started in mid 72.when a buick came into the shop with a single scallop block and needed a short block the only one availible in the later years was the double scallop block.hence the development of the crossover gasket.in my opinion the best stock block is a mid 71 to mid 72,they had single scallops and the oiling system had been updated to bigger passages and pick up,these blocks can take the steel head gaskets also.you can id these engines buy the timming marks on the front cover,the small oiler covers have 8 degrees on the timming tab the large oilers have 12 degrees,AJ
