Auburn247

iTrader: (3)

I'll start with the info truck is a 2011 GMC Sierra z71 ccsb 5.3l. Current mods are volant cai, kooks 1 1/78 long tubes with high flow cats, magnaflow catback, tune and leveled running 33x12.50-20. Truck is my daily driver and tows a camper and boat during the summer months. I put a cam kit together about a year ago and due to this and that haven't installed it yet. My current cam is a comp stage 2 Vvt 214/228 .559/.571 114lsa. Now I'm thinking of Texas speeds stage 3 Vvt truck cam 216/220 .600/.600 112lsa. I have plans for FI(tvs1900?) in the future. I don't wanna have idle issues or cold start problems but don't mind a little chop.

Any advice is appreciated.

Slow05CC

iTrader: (1)

The VVT 216/220 on a 112 would be a good little cam for that set up. The cam is still mild enough for you factory converter, and when tuned right you should not have any issues with cold start, surging, or pushing through the brakes.

You will need a comp 5456 limiter and a pac 1218 spring with hardened pushrods.

Auburn247

iTrader: (3)

I have the limiter, hardened pushrods and comp 918 springs. I also have circle D 278mm converter (3000-3200). I was thinking of have the heads milled, port polhised and maybe an angle job on the valves

Slow05CC

iTrader: (1)

I would check with comp and see if those springs will handle the .600 lift cam. I know they claim to be a .600 spring, but not sure how close to coil bind that will put you. I would be careful about milling the heads. Milling will up your compression. As you sit with the OE heads you will be around 9.9 - 10.0 compression. Milling 30 thou will get you around 10.6 compression. I know those small positive displacements blowers like a little compression, but I wouldn't push it unless you have a really good tuner.

Auburn247

iTrader: (3)

Thanks for the replies blown. I could be wrong (bit of a noob) but I thought I was sitting at about 9.6 compression now. That's why I was thinking of having the heads milled to try and get to 10.1. It's a lc9 with 243's. Maybe I'll just get them ported and polished with angle job. I'll check on those springs as well I was thinking about that myself. As far as Vvt cams go would you choose the tsp over the comp are there any better ones out their? Thanks again for the info

Auburn247

iTrader: (3)

Sorry not blown but slow

Slow05CC

iTrader: (1)

you are correct on the LC9. Those should have 9.6:1 in the 10+ trucks. The 9.9:1 would be the compression for the LC9 07-09 trucks.

Getting your chambers down to 61cc would get you right at 10.0:1 compression with a 51 thou gasket.

64.45cc milled to 61.00cc would be about 25 thou. You will need shorter pushrods ( most likely 7.375 ) and I would run the LS1 MLS gaskets which are 51 thou compressed.

07NBSChevy

LMG 5.3s had 9.9:1 Compression with 243 heads as well.

I would upgrade to dual valve springs if you stick with the .600 lift cam. Just to be on the safe side.

Stock pushrods should be 7.375", or they were on my 07 Gen4 LMG 5.3. I milled the heads to 63cc, 0.045 head gasket and came up with 7.325" pushrods at 0.070 preload, oddly enough. I figured I would need 7.350 but that ended up putting me at 0.090+ preload.

Auburn247

iTrader: (3)

Thanks for the feed back fellas looking into dual springs and shorter pushrods. Now just gotta sell some stuff