I am putting together a 455 to put in my C20 pickup, which I plan to use as both a daily driver, and for towing my skylark to the track. It's a '76 block .030" over, with '72 heads. What would optimum rod/main clearances be for this application?
Man talk about a clone. Just did the same, 76 block .030 over with '72 heads (stage 1 converts), In the mighty words of Greg Gessler..."Its all stock":Brow: . Did the same with clearances as JB stated in his reply. Engine is going in my tow car Centurion convertible, the orig 455 logged over 142K and is extremely tired. Now I can tow and play with comfort. Or I should say, "Towing Fast with Class" as my license plate frames now say.
Re: Re: Bearing clearances for towing application Which intake manifold did you use on your setup? The only 455 intakes I have are a '72 intake with AIR and a '76 with EGR. I was leaning towards the EGR intake, I figured that could even be beneficial since my compression is at the high end of the limit for 87 octane, and from what I've read, EGR helps to quell detonation under part throttle. Just out of curiousity, what compression ratio and cam are you running? Thanks Scott
First off my mistake it's a '73 block not a '76 block. I'm using an aluminum B4B intake I had lying around. The heads and intake use to be on my street set-up way back in the 80's. Also had an old KB deep oil pan and pick-up. With the pistons I went with .030 over cast replacements low compression pistons. (see below) The rods & pins were unused new old stock from those short blocks that some of us scapped up years back (the block was used for the racecar) Basically the engine was a combination of cleaning out the parts shelves in the garage. I do have a posi unit for the car and may be looking to replace the 2.70's gears to give the car a little more low end pull. Not too much though as I prefer the better mpg. With my old engine I could get away with running regular when not towing and no AC. Sometimes with the AC under load she would ping a bit. When towing the best octane available at the pump is a must. The poor thing would have the valves jumping through the hood if I ever ran regular while towing and hit a few medium hills. Not towing cruising at 70 mph to Flint this past July with the AC on I averaged 16.8 mpg, with every other tank filled with super. When towing??? it drops around 10 mpg with no a/c. I'm not looking to rock the world with this engine, just want it to be a strong stocker. The only playing around is setting up a choke for the carb as the intake has no provision. No egr set-up either. What I am installing is a timing control dial from MSD (under 100 bucks) I can dial back the timing a few degrees if I get any detonation when towing and hitting those huge hills. I will be out at Norwalk with it, and hopefully IF my race engine is done in time, I'll be towing my '70 GS racecar. Rick
