Boss Valve springs Vs Pac1234X spring for supercharged built block ? What’s the difference ?

[Unas2k5]

One of my friends told me that I should get the pack 1234 springs instead of the boss valve springs on my new short block being built by Brenspeed what do you guys think what is the difference ?it will be for a supercharged application.

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[K4fxd]

Valve springs go in the head, not the short block.

I'd ask the engine builder if you are rebuilding the heads also.

 

[Unas2k5]

Valve springs go in the head, not the short block.

I'd ask the engine builder if you are rebuilding the heads also.

Thanks and I really have no idea.
I read on the invoice that I was going to get boss valve springs so I assumed it was part of the block.

 

[K4fxd]

If I had a choice I would use the PAC springs 92 pounds on the seat VS the boss at 67.

 

[WCRookie99]

Unless they upgraded the BOSS valve springs since 2012, answer is definitely no. This was the weak link in the BOSS 302R I had and were replaced after about 1000 race miles as the engine ran flat.

You need to make sure it’s not those valve springs. This was not just my engine, my understanding all of these that ran at high RPM saw the same failure.

The Roush-Yates rebuilds fixed this issue plus others. You need to find out what was used

 

[Jackson1320]

all 2015-2017 coyotes have boss springs stock, f150 and mustang.
they are giving you a stock spring and making it sound good. are you still sure you want to go with them for your build

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