440 engine heads/springs

I have an original 1970 date coded 440 engine out of a Chrysler New Yorker. Are the heads and springs the same as a commando 440? I know the cam is different.Any info is helpful.

hi
heads are the same the springs are not !

hp motors had a redspring with a inner flat damper !

so the valves are the same size? I put HP manifolds on the engine. The intake is the same too as the commando? Will the springs need changing if I put a mild cam in the motor?

Valves are the same size...Intake my be diff number? but you won't notice a diff in perf. Hp exhaust fits fine. Please define "mild cam" When in doubt? change the springs to cam manuf. recommendation

Springs are cheap and using 40 year old springs even on a stock cam makes no sense??
Just to give an idea comp performance springs at Mancini racing
http://chucker54.stores.yahoo.net/comcambrbhig.html

ok...can replacing the springs be done without pulling the heads?

yes,they can be swaped with head on engine

short piece of rope in the sparkplug hole,hand crank it till the rope is compressed against valves to hold them

hand crank spring compresser and swap the seals while your there is a good idea

IMO,never liked the air hose trick,to easy to drop the valve,,been there and had to pull the head..might have helped to have the piston at top..which I did not do

I used a KD tool hand crank compresser from napa..about 60$



new spring to match cam is a must and good insurance

thanks for the education guys. Will changing the seals and springs help with being able to be burn unleaded gasoline better? What do they mean about hardened seats? Sorry if I got off subject

no,seals,seal the valve stem were it slides in the vlave guide to keep oil from working down the stem into the comb chamber,where it burns and cause the engine to smoke.

those heads have the hard seat already for unlead gas..

look for pits on the exhast valve edge and the seat part in the head that the valve seals off on,pitts cause it to leak.

before you take the valve out,set it up and pour some water in the port to see if the valve leaks

thats 1 way to see if it needs a valve job.

which they regrind the seat and valve edge with 3 angles or more,to seal it and not leak. doing a valve job at the machine shop..

with the spring off,see if you can move the valve stem tip back and forth.that checks the wear on the valve guide..

OH! my bad,I see its a 70-440 new yorker

what heads are on it?,it could have been swaped since 1970

I was thinking #452 heads from 75 and later

dont think the 70 had hard seats yet.

nah all original running engine..heads are what came with it. I was wondering what is different on the engines to get the Hpower

is it safe to do a cam,lifters, timing chain, valve springs and not do a valve job? Does Heads have to be pulled to replace the hardened seats?

yes,they have to come off for seats to be milled and pressed in.

yes,you can do the cam,lifters,t-chain,springs,seals,with them on the engine

I have done a few with out a valve job

with the rockers and shaft removed use a straight edge across tips of valves

if any are sticking up higher than others, then most likly it needs a valve job cause the valves are sunk into the heads,IIRC

You have 906 heads which didn't have (& didn't need to have) hardened seats as '70 gas had lead in it but there hasn't been much or very little lead used since the mid 70's so between that & the 40 yrs of use I'd sure think the heads need some major attention especially if you are planning on some serious hot rodding. I see heads for cheap all the time and you might get a set of later hardened seat ones & go thru them to have them ready & minimize your down time & if you want to stay original which I didn't get the feeling you did, you could redo your 906's w hardened seats on the ex side & as said new springs also to go with a new cam/lifters but then most likely the valves are also probably shot esp the ex's as they run hotter and with the amt of $$ that this endeavor will up taking to do it right you might consider some stealths s

wow! I already have 906 Heads. engine has 86,000 miles on it. But like u said it is 40 years old. The car runs strong now. I just wanted to get that additional pop like the magnums or commando engines. In essence, I have a Magnum minus the Cam?

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The car runs strong now. I just wanted to get that additional pop

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does it have an AVS carb? and all oe AVS's were emission carbs. I'd suggest an eddie strip kit to richen it up (fill the domed metering rod caps w epoxy to make them flat) and different dist springs/shorten the slots which will give you the most bang for the buck & if the long block is healthy or after you get it healthy I'd attack the most restricted area of the whole package 1st which is usually the manifolds and restricted exhaust.