just use machinest dye to check valves
valve grind compound leaves a line- right
but the valve gets bigger with heat and the line is no longer in the right place
you are not building a model A or Chevy stoveblolt
rumble got it right several pages ago
me- stroked 340
but wait- that's a 360
much easier parts availability and on the street cu in rule
cast cranks do not break and are a lot cheaper than forged
most power per dollar starts with a magnum takeout
look at it another way and start with heads
make sure you have a good finish on your valve stems
some cheap valves have the finish of files
I put a fine finih with a Sunnen stem hone to give a nice crosshatch but a few strokes with some wet or dry paper works
what you are missing are normalized seat durations
looking at your list the clear winner is the shorter lunati
just looking at how much shorter @.050 and the lift
340 cam would suck on a 8.25 motor- it's way bigger
you want the best get mike jones [email protected],006 cam has 460 lift
that crower post...
do not lap
determine valve or seat
you can check runout
or swap a different valve
if it's the seat the whole head has to come apart if grinding
using a cutter not so much
I touch all new valves, od hone the stems and check runout
chk the guide clerance seats etc
The [email protected] duration on that summit cam pencils out to need about 9.7 compression ratio, same as 264 @.006
problem is it has no lift or area under the curve
what did you figure your compression is now that you have your heads?
did you post your deck clerance etc?
if you do have around 9.7 true...
just pencil it out both ways
just because you can do it does not mean you should
A 360 magnum may be less expensive to buid even if you have to buy a core
or just stick one in and go
and do not use that cam even if it's free
That Isky camHL hyd (not) us 50 year old chevy profie Two Strikes and expensive
we have much better springs available today
We used to sell a lot of Megacams as they will overrev without complaint
you can do a lot better than that long duration low lift profile
still do not think more lift is going to help with mild ported iron heads and you can go turbulent
what I would do is advance the cam 4 degrees and try it
if no change or loss then retard 4 degrees
any change will tell you if intake close and duration should be changed
new heads will give the...
you would have to flow them to tell
running open headers or through the mufflers?
I doubt slightly ported could use .600 lift
does the duration give you the rpm range you want?
how about a pic of a stripe on the top of the valve stem
you may need a b3 kit
or change heads
the TF heads do not...
is this an early hight compression 318 or a late low compression?
either way the Summit cam will cost you torque
low compression motor the 250 Voodoo is your best choice for a shelf cam the higher compression motor the 256
using stock gears and converter
post your true compression and we can...