I need a little help. I plan to rebuild my 455 before spring. And do I spend the money to convert my heads to stage 1 or keep the smaller valves? My 455 is a 72 I have Hyper 30 over pistons and I will deck the block to get 10 to 1 out of it. I will be running a crane cane #850631. I would like to get 400+ Hp with a 200-4R, and 3.55 gears. lift @ valve 464 in 480 ex 1.6 rockers cam timing @ .050 intake 8 BTDC 38 ABDC exhaust 52 BBDC 2 ATDC duration 226 in 234 ex Thanks for any input. Vic
Vic, What rockers are you running? If you have the 72 rockers, then the ratio is 1.55:1 The lift would become around .450 .465 if I did my division/multiplication correct.
Hey Vic, One thing a lot of people overlook when decking the block and milling the heads is to check the pushrod length. Not sure how much excess depressing a lifter can take before it either bottoms out or fails. Might be worthwhile to buy one or two adjustables from TA and confirm the length. The cost of a couple pushrods is pretty cheap insurance.
Sure Kelly, A good valve job is a major component of a street-strip port job, and will improve any cylinder head. JW
VIC. with those heads worked over, and that 226 duration cam with 10 to 1 commpression you should be able to get 400+, i would think even threw manifolds, thats if you have a free flowing exhaust, and everything was set up right
I agree with Jim on this one if you are working on a budget and you have the choice of converting to stage 1's with no port work or porting stock valve heads you will be further ahead to port the small valve head. Stock stage one will flow between 218 and 226 on my bench most are closer to 220. I did a basic street strip set for a guy here in Michigan and used his stock valves and we ended up at 248 and had good low lift numbers. We did back cut the stock valves and but a 3 angle VJ on them. The valve job was nothing exotic Standard Street set up. I would definitely port the stock heads.
