quick question(s):

im upgrading the springs on my heads to the lt4 springs. I already purchased the springs, but didn't realize that the cups that hold the springs in place inside the heads would be too small. The lt4's originally had shims rather than cups. pn 10212809. Should I just order new shims rather than trying to find cups that fit? I am having a heck of a time with that btw. Will this even work, or do I need cups? I originally ordered a kit, but it only came with the retainers and clips and all. No cups or shims.

What about the extra spring that coils inside the main valve spring? Does that have to fit tight"? Do I need it at all? What is it called? Did the original lt4's have that? If so, what is the part number on that?

Thanks

 

P/N 10212809 is the correct cup / seat / shim for the ZZ4 /LT4 springs

The green stripe LT4 springs do not have a damper inside

 

What heads are you using ??

 

Brand Summit Racing
Manufacturer's Part Number SUM-1065
Part Type Camshafts
Product Line Summit Racing Street & Strip® Camshafts
Summit Racing Part Number SUM-1065

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 1,600-5,400
Intake Duration at 050 inch Lift 216
Exhaust Duration at 050 inch Lift 216
Duration at 050 inch Lift 216 int./216 exh.
Advertised Intake Duration 272
Advertised Exhaust Duration 272
Advertised Duration 272 int./272 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.454 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.454 in.
Valve Lift with Factory Rocker Arm Ratio 0.454 int./0.454 exh. lift
Lobe Separation (degrees) 110
Intake Valve Lash 0.000 in.
Exhaust Valve Lash 0.000 in.
Computer-Controlled Compatible No
Quantity Sold individually.

 

Agent86 asked what HEADS ; not what cam

 

I ordered GM PN 10212809 since I'm going to be swapping out the springs on my 91 L98 113 heads to support the prospective ZZ4 cam.

It's a hardened steel shim with a raised center to index the spring. it's not the usual totally-flat typical valve spring shim.

 

Sorry. I must have been distracted.

Brand Trick Flow Specialties
Manufacturer's Part Number TFS-30300001
Part Type Cylinder Heads
Product Line Trick Flow® Super 23® 175 Cylinder Heads for Small Block Chevrolet
Summit Racing Part Number TFS-30300001

Cylinder Head Style Assembled
Cylinder Head Material Aluminum
Cylinder Head Finish Natural
Combustion Chamber Volume (cc) 56
CNC-Machined Combustion Chamber No
Intake Runner Volume (cc) 175cc
Exhaust Runner Volume (cc) 67cc
CNC-Machined Intake Runner No
CNC-Machined Exhaust Runner No
Combustion Chamber Style Heart
Intake Port Shape Rectangular
Intake Port Location Standard
Exhaust Port Shape D-port
Exhaust Port Location Standard
Spark Plug Style Angle
Intake Valves Included Yes
Intake Valve Diameter (in) 1.940 in.
Exhaust Valves Included Yes
Exhaust Valve Diameter (in) 1.500 in.
Valve Springs Included Yes
Maximum Valve Lift (in) 0.480 in.
Outside Diameter of Outer Spring (in) 1.250 in.
Damper Spring Included Yes
Number of Springs Per Valve Single
Retainers Included Yes
Retainer Material Chromemoly steel
Locks Included Yes
Lock Style 7 degree
Valve Stem Seals Included Yes
Valve Stem Seal Style Viton® fluoroelastomer
Rocker Arm Studs Included Yes
Rocker Arm Nut Thread Size 3/8-24 in.
Rocker Arms Included No
Rocker Arm Nuts Included No
Guideplates Included Yes
Guideplate Pushrod Size 5/16 in.
Valve Cover Mounting Style Perimeter bolt
Accessory Bolt Holes Drilled Yes
Intake Valve Angle 23
Exhaust Valve Angle 23
Valve Guides Included Yes
Valve Guide Material Manganese bronze
Valve Seats Machined Yes
Valve Seat Machine Style 3-angle
Valve Seat Material Ductile iron
Steam Holes Drilled No
Oiling Style Through pushrod
Machined for O-Ring No
Heat Crossover No
CARB EO Number D-369-6 (pdf)
To see a list of qualifying vehicles, enter CARB EO Number D-369-6
Quantity Sold as a pair.


Yeah, I have seen the picture of the shims. So the question is, should I purchase the shims or look for cups? Seems like at this point it makes sense to purchase the shims. THey are 1.80 each through gm.

 

The reason I asked was, if you were using the GM heads, I was going to offer some advice. Since your not, there is no need.

The LT4 shim is a base and it keeps the spring centered around guide boss. Get them.

 

Thanks. That was the assumption, but I didn't want to purchase those if the cups were really what I needed. Ill put the order in tomorrow.

Thanks for the advice.

ps. I will post pictures of the whole project when I am done.