Don Terrill’s Speed-Talk

Find true coil bind on your springs using a spring tester, then set them up .050 away from there with the I.H. This should cure any problems with the spring setup. Using Crane lifters we set them down one full turn HOT.
It also helps to measure actual lift at the valve with the actual springs your running using a solid lifter and zero lash...especially on a sb mopar!
Brian

Bump. This is an old thread, but thought I'd update in case anyone searches with the same query to get an answer. The car has been running flawlessly for the past four years . . .

I measured lift at the valves and ended up with installed heights of about 1.735" (.584" lift) intake and 1.755" (.603" lift) exhaust for just over .050" coil bind clearance as directed. The beehive springs are Manley #221438.

Everything worked a treat and the engine easily revs to its 6800rpm cut-off with 2.05"/1.60" valves and 1.65 T&D rockers. As a bonus, the engine made another 30rwhp on the dyno with an increase from 1.5 to 1.65 rockers, 2.02" to 2.05" intake valves, 0.035" quench and slight cleanup of the heads (port match, CCed to 64cc).

FYI, if anyone is thinking about installing LS valve springs on small-block Mopar Edelbrock heads, I'd say go for it.

PSI also makes a spring part #LS1511ML that has 384lb rate and 130lb @ 1.800" vs the Manley springs with 353lb rate and 150lb @ 1.800".

good info, thanks for sharing.

my father is running a SB 408 mopar with edelbrock heads, with the PSI 1511ML springs that I setup a few months ago.
1.6 'economy' shaft rocker from PRW. So far so good
lift was .546 on both, cam 242/248 @050
2.055 chevy 11/32 valve intake and 1.60 exh

I ended up with the Manley spring because it had the same open pressure as the PSI at my lift with 20lb more on the seat. The move from 1.5 Crane to 1.65 T&D rockers was the killer - 10% more lift, faster opening and closing events, but the T&D rockers are also much bigger and heavier than most other roller rockers, so need a bigger spring to stabilise.

I should clarify, I'm running the PSI 1511ML with flat tappet, not roller
decent Johnson cobalt faced lifter, oiling 'flats' ground down the sides
P55 cam core
if hyd roller I would like the Manley's like you went with as well for more spring force.