I am building my 383 right now and have been asking a lot of the same questions that I see others are asking. I pulled the motor out of my 1967 plymouth sport fury. The intake and heads numbers match for the 67 Plymouth. When I cleaned the block it is stamped F383 HP which tells me it is a 1970 block. So, someone has had this apart in the past. I was wondering what lifters I needed to order for it since it has a 1970 block and 1967 (516) heads. I was told to order for the block. So, I ordered a comp cams cam kit with lifters for 1968 and up. Well, I get them and compare them to the old ones and they are a little taller . The ones that were in the block were the 1967 lifters and 1967 push rods. I have been trying to read all I can to find out about the differences in these 383's. I have found that the 1967 push rods are 5/16 on one end and 1/4 on the other. The 1968 and up pushrods are 5/16 on both ends. The 1967 lifters are a little shorter than the 1968 and up. And the 1967 lifters made for the small 1/4 inch rod end to fit into them were the 1968 and up are made to only fit the 5/16 rod. What I am wanting to do to my engine and I don't know if it will work or not is : put a larger exhaust valve in the heads. The 516's are closed chambers but they have a 2.08 intake and a 1.60 exhaust. So I am going to put a larger 1.74 exhaust valve in it . I ordered Milodon megaflow racing valves for it. I'm going to have a 3 angle valve job and have the heads bowl blended. I ordered a compcams cam kit for it. It has a .470 lift and a 270 duration and 224@50 for both the intake and exhaust. It is supposed to be the largest cam you can run a stock stall convertor with. I ordered adjustable roller rockers for it . I also ordered a adjustable pushrod that is used to measure push rod length. What I plan on doing is with the taller lifter and higher lift cam is putting the head on the block bolting a few of the head bolts snug and from what I read about the adjustable roller rockers is you want to have no more than 2 threads showing out the bottom of the rocker arm, adjusting the rocker arms to 2 threads installing the adjustable push rod and getting #1 piston to tdc were both valves are completly closed. Then adjusting the push rod to the length needed. Then ordering pushrods to the length that I need. My question is do you think this will work or is there something else I should do ?
. If you haven't done so already suggest that you start a build thread on your 383. The tech wizards on this board may not be looking here.
