Pac vs Manley

[FED 387]

Both make "good" springs--- too many variables to ask that question--- need info on Cam lift- suggested spring pressures- RPM range engine will be operated in/spring diameter/installed height etc./spring treatments polishing etc. etc.-----might want to look at PSI also compare the 3--- PAC & PSI generally are a step above Manley due to their steel/manufacturing treatments etc. etc. but I'm not saying to use one over the other it all depends on your set up---FED 387

[Tom Goldman]

I have to say the last set of Manley 448 springs I got were the best ever from Manley.
Over 200 runs with no broken springs and only 10-15# loss of pressure across the board.
And that is on a 8300rpm Big Block with a .900 lift cam .
I've used PAC , PSI and Manley , It seems Manley may have caught up with the reliability. AND they always pay the contingency , had issues with the others.

[richie 2]

yes time for a new set on my 327ci...same recommendations? matching retainers & locks or r they a different brand...tks.

[trmnatr]

Crane Cam's springs are also good. They have some made by PAC and some not. Their 1.55" and 1.625" is made for them and are excellent (96886 and 99880), and their Posi-Stop or standard retainers fit correctly including ID locators.

I like both Crane and Manley

[Ed Wright]

I have been using PAC 1356 springs (1.5" dia) for a few years now. I put new springs on every year, just to be safe. Just an LT1, mine never sees over 8500. Usually 8300 at the stripe. Have never broken one, and have never seen much pressure loss. I have three sets sitting here I would have no problem using again. I can torque the center head bolts with these 1.5" diameter springs installed, and don't have to clearance the rocker arms for them. Best springs I have had.

[63corvette]

I have used PAC, PSI, and Manley.

PSI never paid me contingency, even after repeated calls and emails so I stopped using their springs.

Manley always had breakage issues. In 2010 I could not make over 5 to 6 passes before changing a broken spring. Manley even admitted they had an issue and wanted to give me more springs free. I declined and changed to PAC. Issue solved.
PAC over the years have been slow to pay contingency, however in 2016 they paid quickly.

PAC is and would be my choice.
I still use them and have not broken one in years and they hold their pressures for a full year.

Just My 2 Cents
Rick Cates

[drgrcr1156]

Originally Posted by Tom Goldman

I have to say the last set of Manley 448 springs I got were the best ever from Manley.
Over 200 runs with no broken springs and only 10-15# loss of pressure across the board.
And that is on a 8300rpm Big Block with a .900 lift cam .
I've used PAC , PSI and Manley , It seems Manley may have caught up with the reliability. AND they always pay the contingency , had issues with the others.

Tom,
What rear gear are you using with that combination?


Bob