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Cam selection help, 87 LG4

Old 04-15-2019, 06:42 PM
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Cam selection help, 87 LG4

Hey guys, quick background. I have an 87 LG4 Non CC Carb, Edelbrock 600, mid length headers, true dual exhaust, double roller chain, dual springs and lastly the "ramjet 395" cam (roller) which was recommended on this board for a 305. Stock heads as well. Also I should add I have a 9 bolt posi rear with 3.27s but have a set of 4.11s on hand which will be going in when i pull the car out of storage. The car is a 5 speed. (EDIT I guess all my mods are in the sigature, lol)

So short and sweet, everything runs great and I love the car but think it could benefit from more cam. Before we go down the 350 road I want to say I am happy with my 305, it still has low miles and runs great. Not looking for 400 horsepower or anything like that.

Would really like a cam that is more aggressive in nature. Lopey idle and more alive on the mid to top end. The ramjet cam idles smooth as stock and honestly I'm not sure if i noticed a performance improvement or not, although the numbers are better than the "peanut cam" it came with. A lot of guys will say not to over-cam a motor and especially a 305 but I think I can definitely go more aggressive than the ramjet that is in it.

Open to some friendly discussion, hoping you guys can help steer me in the right direction! Love making the car act like a different animal every couple of years.
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Old 04-15-2019, 06:55 PM
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Re: Cam selection help, 87 LG4

Numbers from what I can find for those that are interested

peanut cam
179/194 .350/.384 109 lsa

ramjet cam
196/206 .431/.451 109 lsa
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Old 04-15-2019, 10:56 PM
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Re: Cam selection help, 87 LG4

LT4 Hotcam
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Old 04-16-2019, 09:42 AM
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Re: Cam selection help, 87 LG4

Originally Posted by dmccain View Post
LT4 Hotcam
I would use the SPO 357 HP 350 cam in that setup.

215/223 @ .050", .473/.473", 108 LSA, 109 ICL

Would only require a spring upgrade on the heads rather than head modifications.

The slightly shorter duration and tighter LSA should bring on the torque a little sooner than the Hotcam. In a 305 with stock heads I would install it with an adjustable timing set in the 4* advance position. Should put it on a 105* ICL or 3* advance from centerline.
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Old 04-16-2019, 05:20 PM
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Re: Cam selection help, 87 LG4

That SPO cam would be great Fast. I liked the K1104 in my flat tappet LG4 engine.
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Old 04-21-2019, 07:08 AM
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Re: Cam selection help, 87 LG4

Thanks for the responses guys. I like the specs on the SPO cam. Could not find if it has a fuel pump lobe (or on the LT4 cam for that matter) which i would need

I have the trick flow tfs-16848-16 springs and comp 2136 timing set so think that should he sufficient enough? Also running stamped 1.6 roller rockers
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Old 04-21-2019, 07:57 PM
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Re: Cam selection help, 87 LG4

Originally Posted by Fast355 View Post
I would use the SPO 357 HP 350 cam in that setup.

215/223 @ .050", .473/.473", 108 LSA, 109 ICL

Would only require a spring upgrade on the heads rather than head modifications.

The slightly shorter duration and tighter LSA should bring on the torque a little sooner than the Hotcam. In a 305 with stock heads I would install it with an adjustable timing set in the 4* advance position. Should put it on a 105* ICL or 3* advance from centerline.
Fast355, you would really go that big with an LG4? I can see using it in an L69. Just asking.
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Old 04-21-2019, 09:06 PM
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Re: Cam selection help, 87 LG4

Originally Posted by NoEmissions84TA View Post
Fast355, you would really go that big with an LG4? I can see using it in an L69. Just asking.
The factory 87 LG4 has flat top pistons and 081 TPI heads. When you open up the exhaust it is the same as a L69 at that point save for the cam.

I had a flat tappet 218/218 @ .050 Lunati HE 268 cam with 1.6 rockers in the L30 305 Vortec in my 1999 Tahoe. With a S10 converter stalling 2,500 rpm it ran great in that heavy Tahoe. Ran it with all the stock 350 parts and later added headers, 2.5" dual pipes to the muffler, a ported intake manifold and a Volant intake.Was still perfectly driveable with the stock 350 converter that stalled 1,500 rpm. With the stock low stall converter was a little doggy under 30 mph compared to a stock 350 but came on strong above that even with the stock manifolds. Ran better than the stock 350 Vortec did in the same truck. With the converter, headers, ported intake, CAI and exhaust it ran much better than a stock 350. Also swapped the clutch fan for 2008 Tahoe E-fans on the 34" radiator. It put down 280 RWHP and 300 RWTQ on heavy 20s which was enough to kill the 120K mile 4L60E. At that point I swapped an 8.1/4L80E in the 305/4L60Es place. With a 3.42 gear that 305 would pull the Tahoe on flat land at 1,700 rpm @ 70 and manage 23 mpg. It ran at 75-85 KPA map which is about 5-7 in/hg vacuum but it did not seem to care with a good PCM tune. At 70 mph it had great passing power if you floored it to get a downshift to 2nd gear which put it at 4,500 rpm. 4,500 to 5,500 rpm in 2nd gear was very quick and had the speedo to 90+ in no time.

Last edited by Fast355; 04-21-2019 at 09:20 PM.
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Old 04-21-2019, 09:22 PM
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Re: Cam selection help, 87 LG4

He also claims to have Trickflows which flow better than any production 305 head. Honestly with a converter that stalled 3,000 rpm or so and a deepr gear like a 3.73 I would run even more cam. Something like the GM846. 222/230 @.050. I think people fail to realize with a decent converter and gears that a HOT 305 does not mind being cammed similarly to a HOT 350. The stroke is the same and it is still somewhat hard to kill torque off in a 305. I had a L82 cam in a 9.5:1 305 with ported 081s in my G20 van with a 2,800 stall and 3.73 gears. It 60' much quicker than the stock cam, stock converter and factory 3.08s and only took off harder as the RPM climbed.

Last edited by Fast355; 04-21-2019 at 09:26 PM.
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