is there a spec for this and or is it the same as the LCA & if so what is the spec for that? thank you for your time.

My 1983 Truck Factory Service Manual (FSM) lists these cam specs for the 318 engine. Which are the same cam specs in my 1971 FSM too.

Intake Opens = 10 degrees BTDC
Intake Closes = 50 degrees ABDC
Exhaust Opens = 52 degrees BBDC
Exhaust Closes = 16 degrees ATDC
Overlap = 26 degrees
Intake Duration = 240 degrees
Exhaust Duration = 248 degrees
Converting the numbers to get 26 degrees overlap would makes the Lobe Separation Angle (LSA) = 109 degrees.
To get the intake and closing events to agree with crank position, the Intake Centerline would need to be 110 degrees.
The FSM says the Intake valve lift is 0.373", and exhaust is 0.400".
That is a very slight difference compared to the 1971 FSM that says 0.373"/0.399" lift?

Good comprehensive info. Thank you! I will dig out my old cam books & bone up on ICL/LCA. what is going on is I replace the leaking t chain gasket & took the opportunity to toss in an new chain/gearset that I had laying around & I advanced it 4 deg on the keyway & I just got it running & it runs good but the timing is 18 & was just thinking (that's probably the problem!), that turning the cam a bit (in effect) CCW to advance it would have retarded the dist timing so I just thought I'd ask. I had never checked the timing beforehand (recently) so I dont know what it was before but I think the OE spec is way way more retarded than 18 (appears to be an untouched engine). I got to thinking that maybe I put it in on the 4 deg retarded keyway by mistake cuz I coulda swore that I checked the timing way back & it was ~15. thank you for your time. EDIT So I was potentially gonna degree it to find out for sure but I have (much) more important things I need to get after & after the carb rebuild it runs real good.

If you did in fact advance the cam, that would also advance the ignition advance as long as you never touched the distrib. You may be good.

it is a greasy pig but it does run good now but OK if I turned the cam in effect CCW to advance it, that would move the reluctor CCW so it would then need to move forward CW to fire and at that point the dampener would be further CW (retarded). Am I turned around on that reasoning? EDIT did not touch the dist

But when you advance the cam, you set it farther clockwise then where it was before advancing it. You can't think of it like turning a distrib housing counter clockwise to advance ign timing, that's all.

You are right, After you put it that way I grasp it now, going CW is gonna make the intake lobe reach its peak sooner (maybe 102 degrees away from TDC as opposed to 104 degrees away) & that would advance the initial with no other changes. got it now!. Thanks bro. (I had had it in my head that to go from 104 to 102 would be a CCW direction).

My first engine all by myself was a Toyota 20R. With the automatic it was a dog down low. At Tractor Supply I found a Wodruff key the right shape but thicker. Using a flat file I made my own advance key. It worked! more bottom end power. This was in the days of the 55, and top speed didn't count.

Those farm stores can be your friend.

R.

Yeah there is a TSC store here & I might have to get out there (it is on the other side of town) & browse areound. A guy wants to give me a grand for that 95 furd truck I bought for $400 to get me around till I got the Ramcharger up & going (727/tcover seal/rebuilt carb). The guy was not a mechanic & the check eng light was on & it shudders on accell sometimes & I think that worried him (when I replaced the reg to get it back charging (was charging when I bought it) the check eng light went out!) tho it still shudders. it was $200 to license/register it & the voltage reg was 50 some. not a killing but better than losing money on an investment. Hey Dog if I get down to Florida I would look you up, my folks are in Naples and they are 98/86 so it might be now or never

Hey, it's Scratchin' who's in Florida. I am working in Northern Arizona, but my home is Denver. centerline the cam when both intake and exhaust lifters are the same height off the cam. E-burg suggested using a straightedge over the lifters. I used the side of a socket. Yes, the dual pattern cam will be a little different but it's still close. On my engine I got to split overlap then moved the camshaft a little so the intake was a little higher than the exhaust.

RE: Parents...Do whatever you have to do so you will not feel guilty about how you treated them when they die. My mother waited to die until she had seen me one last time. Kids are important to parents.

R.

Those $500 Ford trucks can be handy. Mine is a '77.

Well I told my dad that if he would hold on another year I would come down & blow out all 100 candles (hopefully in (1) breath) for him. I was sweatin that I had put the 3 position cam gear in wrong but when I finally put the light on it it was showing 19 which is 4 degrees advanced from the 15 I remember it was at a year ago so it is all good.