Iron Head Valve Springs

**87IROCLT1** · 12-20-2016, 02:16 PM

Hey all,

I have been browsing this site and other quite a bit but this place seems to have the right people that might answer this question-

I want to replace the valve springs on my LT1 this winter, 94 caddy fleetwood LT1 swapped into an 87 IROC. Stock cam, stock iron heads, shorties, 3" cat back, cone filter to MAF and elbow(minimal restrictions, but not CAI)

I bought a set of comp pro-mag 1.6 rr and want to put those on with a decent set of springs and valve seals. I have read good things about the Howards 98215 and the Bullet Vs2700's, they are both about the same price and from my understanding both will need the damper removed, but I am hoping to get some more input. Seems like most of the threads are older. Also, it seems like Alex's Parts is out of stock with no restocking sight.

I guess I should also mention I want to keep the stock retainers/locks if at all possible. Really looking for a quality drop in spring to handle the 1.6rrs on the stock cam.

The car currently has a t56 to 3:73 gears, so yes i know a cam swap will make things much better, but thats off the table for a while.

Any input you could contribute would be great,

Thanks!

and since i havent posted on here much, here is a few pics of the car until i get my build thread up

**DMBlack** · 12-20-2016, 02:47 PM

I can't really help on what springs to run with the iron heads but when I did 1.6 rockers on my aluminum heads, I ran the springs that come with the LT4 Hot Cam kit. May be an option for you too.

Nice car too. I am a sucker for a clean third-gen especially when they are blue. I will look forward to seeing the build thread and hope someone chimes in that can help with your spring issue.

**87IROCLT1** · 12-20-2016, 04:13 PM

Originally Posted by DMBlack

I can't really help on what springs to run with the iron heads but when I did 1.6 rockers on my aluminum heads, I ran the springs that come with the LT4 Hot Cam kit. May be an option for you too.

Nice car too. I am a sucker for a clean third-gen especially when they are blue. I will look forward to seeing the build thread and hope someone chimes in that can help with your spring issue.

Thanks David,

I have considered them, and they were on my short list, but for some reason everyone seems to rag on them a bit, the valves are heavier etc etc.

This is something i dont want to do again if i dont have to.

**firebird_1995** · 12-20-2016, 07:15 PM

I have nothing to add on the springs, but that's a gorgeous color of blue. Looks amazing on the 3rd gen.... love it

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**Camaro96** · 12-20-2016, 07:36 PM

Nice looking third gen. The LT-4 springs should work fine, but your form head guru @NightTrain66

May be able to shine some light on this subject.

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**SSlowBoat** · 12-20-2016, 10:48 PM

From my knowledge you cant use lt4 springs on iron heads, and also iron heads have press in rocker studs, ull have to have them machined for threaded studs and 1.6 rockers. Why not just swap on some aluminums?

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**NightTrain66** · 12-21-2016, 07:05 AM

I would get the howards 98215 springs and remove the dampers if you ever plan on installing a mild cam in the engine.

If you are going to stick with the stock cam and never upgrade the cam, the Howards 98213 springs are a good choice. They are the exact same spring as the 98215's (same spring pressure, dimensions, etc) but they are not electro polished and a lil less $$.

Lloyd

**87IROCLT1** · 12-21-2016, 07:47 AM

Originally Posted by NightTrain66

I would get the howards 98215 springs and remove the dampers if you ever plan on installing a mild cam in the engine.

If you are going to stick with the stock cam and never upgrade the cam, the Howards 98213 springs are a good choice. They are the exact same spring as the 98215's (same spring pressure, dimensions, etc) but they are not electro polished and a lil less $$.

Lloyd

Thanks Lloyd-

When its time to rebuild the engine I will be putting a cam in it, but I will also be talking with you about heads, springs, valves etc.

Thanks to everyone for the compliments on the car, i will try to get my build thread started today.

**87IROCLT1** · 12-21-2016, 07:50 AM

Originally Posted by Tubby Z28

From my knowledge you cant use lt4 springs on iron heads, and also iron heads have press in rocker studs, ull have to have them machined for threaded studs and 1.6 rockers. Why not just swap on some aluminums?

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Thanks Tubby- figured that on the LT4 springs- i do have a set of AL heads sitting in the shed, but im trying to not get sucked into the "if i do that, i might as well do this too" that gets to be a slippery slope and the funds arent there to catch me.

in a few years those AL heads will be sent off and ill have the short block honed/ringed/bearings etc.

**BALLSS** · 12-21-2016, 10:37 AM

IDK if he 98215 Howards spring can use the same retainers as stock so you may need retainers (see Summit link for "required parts"). I believe you also need to remove the damper spring to clear the valve seals. The specs are also for a installed height of 1.800"so on stock iron heads they will install a little shorter 1.750 ish so the open & seat pressure will be slightly higher. No big deal

https://www.summitracing.com/parts/hrs-98215/overview/

or another option for a direct fit spring for iron heads is Crane 10309-1 kit. It comes with retainers and you can re-use your stock 7 degree locks. I ran these on my iron heads with 1:6 SA RR on a stock cam LT1.

https://www.summitracing.com/parts/crn-10309-1

Get new valve stem seals. Felpro makes a good set typically available at most auto part stores. You want a Viton seal. Lunati also makes them # 78562-16

11/32" x .562