Pyro

If your turbo doesn't make full boost until 3500 rpm+ then that is a sign of a free flowing turbine. Which means that turbo can handle some valve overlap and would work well with a cam with around 270 degrees of duration on both the intake and exhaust.

Turbos typically like cams with more intake duration than exhaust. The theory is shorter exhaust duration makes a hotter and faster exhaust stream into the turbo. (pure exhaust) What turbo are you using? A stock turbo has a small turbine and makes lots of back pressure in the exhaust manifold. So stock turbos don't do well with any valve overlap. If you are using a more free flowing turbine then more overlap can be used.

Gages can vary. I have 2 gages, the same make and model, and one reads 20 psi lower than the other one. More important to see the differences between cylinders. A stretched timing chain can lower cranking pressure. Advancing the chain to the next position can increase cranking pressure by a large amount. Years ago on an old worn out 78 280z, my engine increased cranking pressure by 50 psi by advancing the cam from the 1st position to the 3rd. Check timing marks on the cam/sprocket to see if the chain has stretched.

Use the low speed part of the taurus fan. Cools about the same with 1/2 the current draw.

What turbo did you get from ebay?

I set a "bigger" cam a little tighter. try 0.008" (hot). Most aftermarket cams spec a tighter lash than stock. If someone puts in a regrind cam without increase the thickness of the lash pads, it will tick. Check to see if the lash pads are stock and if the cam is a regrind. Also check the wipe pattern. Aftermarket cams are louder than stock cams.

Get a used 96 to 2000 5.7 vortec engine. Comes with a factory roller cam and vortec heads. Should be able to get a complete engine (fan to flywheel) in good shape for less than 1000. May also be a good idea to get the transmission attached to the engine. I would also get the engine with the complete efi system and get that going too.

Stock cams with stock spring will not have a problem with the new oils. High lift, fast lobe lifts, and stronger springs will create cam lobe wear issues.

I run the T04B-H trim with a T3 exhaust turbine (stage 3). Boost comes on slow and steady, almost feels like a big non-turbo engine. Would work really well for an autocross car, due to the slower increase of engine torque. Makes 5 psi of boost at 3000 rpm and full boost by 3500 (running about 12 psi). The free flowing turbine allows 80 mph driving with 10 inhg vacuum. The stock turbine was at 0 inhg at this speed (starting to make boost). According to the compressor maps, my engine should be in compressor surge at 3000 rpms, but it isn't in real life. I miss the low rpm boost of the stock turbo but i'm not going to try low boost with this compressor due to the surge risk. This compressor is better when used with a stage 1 or bigger camshaft (higher rpm cam), or at least use a NA cam. Finally, the T04B-H clears the intake manifold with out the spacer that is required for the T04E-50 trim compressor.

I took mine out to make room for intercooling pipe. Ending up wedging an one quart plastic oil bottle in the corner and sticking my over flow hose in it. My temps stay low so it doesn't seem to punk anything out, but it is there just in case.

I used the Hooker Super Comps for sbc conversion for a z. I bought them 10 tens ago so not sure if you can still get them. The headers required a little modification to get into the car because the headers were not designed for the setback position (JTR position), plus the scatter shield for the clutch was in the way, and I also converted to 2-1/2" collector flangers for more ground clearance. I also seen some early 70's corvette headers that fit pretty close, but still require mods. I brought the Dart 200cc iron eagle heads and used the springs that came with the heads. The springs were a little stronger than the springs recommended by Compcam for the 292H. I believe Dart heads came with springs for a roller cam. Anyways, the 292H would float the valves at 7200 rpms and pull hard to 7000. However, my best et's were made with 6500 shift points even though I would swear the engine was still pulling very hard past 6500. I have a 5" Autometer tach so I'm pretty sure about the RPMs. Good luck with your cam!

I ran the 292H with my 350 powered z (t5, 3.90 gear, 200cc dart iron eagle, long tube headers, rpm intake, 750 carb). Great cam but a rough idle. Once moving the cam was very streetable. Useable power from 3000 to 7000. Ran a between 117 to 120mph in the 1/4 mile around 11.7 et. Did a best of 10.7 at 135 with a 175hp shot n02. With block huggers, single 2.5" exhaust, old fuelie double hump heads, 292h cam, rpm intake, and 750, it ran 12.7 at 110 mph. So, it drop a full second in the 1/4 mile with better exhaust and heads. 12.3 with better exhaust then 11.7 with better heads, installed in that order. After your head swap, I think the block huggers and 600 cfm carb are your biggest hp killers. And the hp will be choked off even more with the bigger cam. The performer intake and 5500 rev limiter is not good for the bigger cams. I would stay with the rpm intake no matter what cam you use. I don't like air gaps, but like the regular rpm intake. Also get a holley 3310, 750 vacuum secondary. Last thing, a bigger cam will need 20 to 25 degree of ignition timing at idle and use zddp oil additive to keep the cam lobes happy.

I have run both and haven't notice a difference. I have been told that they can handle the same amount of power but both are on the weak side. Syncro's in the wc are better. Like I said, I have run both in my z with a 400+ hp 350 and a 200hp shot of n02 with drag slicks. They will last a long time if you don't slam the gears too hard. Avoid power shifts, fast shifts, and clutch dumps. I feel the GM T5 transmissions are stronger that the Z's rear axles and diffs, as my car tends to break those and not the transmission. You need to use the V8 T5 with the fine tooth splines (26 tooth), the V6 T5 has around 10 splines.

I had a new oil pump fail on me a few years ago. The lid didn't have enough clearance between the rotors and the extra drag wore the oil worm gear off the crank which also put metal in the oil which ate up the engine bearings. Now, I always disassemble my new oil pumps and check the lid clearance. And since then have found a few new pumps that were too tight from the factory. With a cam that big, I would just lock the mechanical advance in the distributor and set it to 35 degrees at idle. good luck!

Use a stock NA cam (internally oiled, 1977+) in your P90 head and you will be fine. In fact, a stock NA cam works better then the turbo cam in my opinion. Good for another 500 rpms of usable power