Smog Era 350 Vortec build.

[ClassicRob]

So after months of deliberation and buying parts, life has gotten in the way and I am scrapping the vintage build and the cheaper crate engine idea for the time being for just a top end build. Truth be told, my mother has dementia and is very close to passing. Hospice is involved...etc. Its hard to deal with. Thankfully, God gave me a hobby to keep my mind busy and messing with all this has kept me sane. So my wife and I agreed that I could do a top end kit on the engine in the car currently. Not wanting to forego that option, I have been on the interwebs all day buying parts to get this done. Anywho...

The engine in question is my 77 Z28 350. Its the typical flat tappet deal using a 010 block and 882 heads. I don't want to chance spinning this deal over 6000rpm so the XE274 cam is out.

This morning I bought several parts including Vortec heads from GM, a GMPP dual plane intake, XE262H-10 cam and lifter kit, Magnum 1.5:1 rocker arms and pushrods, Comp roller timing set and Im about to purchase the carburetor. I also have a set of Sanderson Vortec shorty 1 5/8" headers that I purchased along with a 70-72 dual snorkel air cleaner assembly. Doing some math, I am getting static compression at about 9.2 and dynamic at 7.9 which should be ok. I am looking for approximately 325-375hp@5400-5600rpm with great vacuum, but more is possible.

Again, everything above is purchased. Personally I think it's a solid street car low RPM combination that should at least make the car more fun to drive. The questions I have pertain to the quench, degreeing the cam and vortec head modifications.

With the pistons .021 in the hole, and a .028" head gasket, I would think this is too much quench which can be resolved easily with a thinner head gasket. Is there any problems running the .015" head gasket on a deck that hasn't been machined flat? I would think it should be fine with the thin rubber layer around the gasket but I have heard you want to use a thicker head gasket if you are reusing heads or blocks that aren't recently machined.

Do I install this cam straight up?

Last but not least...
Rumor is these newer Mexican Vortec heads don't flow like the old 062's or 906's but do have thicker decks that are less prone to cracking. Since Vortec heads have hit the market people have tried to make them flow better with sometimes bad results. What does the current way of thinking say about doing some work to these? I do have enough money to send these to a machine shop to get a good valve job and maybe some bowl work and milling done to help maximize the set up.

Again I know I have been all over the place with this deal and I appreciate all the input I have gotten. I know most of the guys here are good guys and I just want yall to know I do appreciate the help. But this is for sure the final iteration of this project, for now. Maybe down the road I can get that vintage build done.

[F-BIRD'88]

In your situation I would bolt the vortec heads on as is.
Ya the later mex heads reportably flow a but less but you can fix that later..
Gasket you can go either way.
I have run the .015" gasket on a flat top motor with.018" deck clearance. no problem.. I like to use the gmpp head bolt kit that has the smaller hex for easy re torque with rockers on.

Should have bought the Isky 201278 cam.
Even if you choose to limit max rpm shift points its still a better cam.

Are you sure this 77 camaro 350 has flat top pistons?

Cam install. The most I might do on that xe cam is move it slightly to a 104° intake C/l.. We're cuttin hairs here.
If you had bought the correct L88 L72 Z/28 LT1 a/c base (cannot get from gm) You sould have easily fit the High rise RPM style intake vs the performer like GM vortec intake.. Rushed choices. Could run your Qjet

[Chris_Hamilton]

Sorry about your Mom.

[travis]

.049” quench is fine, installing the cam straight up is fine. The Mexican vortec’s aren’t as good as the regular 062 or 906 vortecs but are still better in every way compared to the 882’s. If the intake you ordered is a spread bore intake, the Holley 9895 650 VS carb works awesome right out of the box. This thing will run so much better than stock you won’t even recognize it.

The XE262 is also a far better choice for low speed manners than a 234@.050 cam on a 106 lsa (Isky 201278). You will like this setup a lot.

[F-BIRD'88]

Manners are fur school teachers. . With the 4 speed you'd love it.. Yes rougher idle.. Great throttle responce torque and power.

In this situation I would have done nothing.
Stick the stock engine in the car and deal with life , family matters first

[ClassicRob]

Sorry about your Mom.

Thank you. Dementia is a real mfer.

[ClassicRob]

Manners are fur school teachers. . With the 4 speed you'd love it.. Yes rougher idle.. Great throttle responce torque and power.

In this situation I would have done nothing.
Stick the stock engine in the car and deal with life , family matters first

What makes you think I am not dealing with family matters?? Please don't comment on stuff you don't know anything about. smh

[ClassicRob]

Manners are fur school teachers. . With the 4 speed you'd love it.. Yes rougher idle.. Great throttle responce torque and power.

In this situation I would have done nothing.
Stick the stock engine in the car and deal with life , family matters first

What makes you think I am not dealing with family matters?? Please don't comment on stuff you don't know anything about. smh

[cjperformance]

.049” quench is fine, installing the cam straight up is fine. The Mexican vortec’s aren’t as good as the regular 062 or 906 vortecs but are still better in every way compared to the 882’s. If the intake you ordered is a spread bore intake, the Holley 9895 650 VS carb works awesome right out of the box. This thing will run so much better than stock you won’t even recognize it.

The XE262 is also a far better choice for low speed manners than a 234@.050 cam on a 106 lsa (Isky 201278). You will like this setup a lot.

Yep that XE262 will toast the Isky cam everywhere but right up top. For a street mild combo, thats still nice to simply cruise, that dual plane and 262 cam combo will be great.

[rebelyell]

Sorry 'bout your mom. Already been through the dementia & it's subsequent end result. Perhaps you already know this, but if not; a passing and the period following it often reveals some financial surprise(s). In time, your family's position may become improved or even degraded. Also, emotions / visions/ spirituality tend to change in time; sometimes in unpredictable ways too. If your loved one's estate is subject to probate; many of its assets may be frozen while ample time is afforded for any claims / liabilities (assets as well) to be brought to light. Prepare yourselves for unforetold change.

Suggest primary focus remain on mom's care & aftercare; while putting the toys on hold until some 12-18 months after her passing.

[ClassicRob]

Sorry 'bout your mom. Already been through the dementia & it's subsequent end result. Perhaps you already know this, but if not; a passing and the period following it often reveals some financial surprise(s). In time, your family's position may become improved or even degraded. Also, emotions / visions/ spirituality tend to change in time; sometimes in unpredictable ways too. If your loved one's estate is subject to probate; many of its assets may be frozen while ample time is afforded for any claims / liabilities (assets as well) to be brought to light. Prepare yourselves for unforetold change.

Suggest primary focus remain on mom's care & aftercare; while putting the toys on hold until some 12-18 months after her passing.

Give me a god damn break! I dont want to talk about my moms dementia! I come here to get in a better mood. Dads still alive and this has been going on for 10 years. The house, funeral, nurse, etc. is already bought and paid for. This isnt anything new. The car I am modifying is the same car I have memories of when I was a kid. The one she used to drive! Im trying to get it running good, so can we move on??

[skinny z]

The engine in question is my 77 Z28 350. Its the typical flat tappet deal using a 010 block and 882 heads. I don't want to chance spinning this deal over 6000rpm so the XE274 cam is out.

This morning I bought several parts including Vortec heads from GM, a GMPP dual plane intake, XE262H-10 cam and lifter kit, Magnum 1.5:1 rocker arms and pushrods, Comp roller timing set and Im about to purchase the carburetor. I also have a set of Sanderson Vortec shorty 1 5/8" headers that I purchased along with a 70-72 dual snorkel air cleaner assembly. Doing some math, I am getting static compression at about 9.2 and dynamic at 7.9 which should be ok. I am looking for approximately 325-375hp@5400-5600rpm with great vacuum, but more is possible.

. Personally I think it's a solid street car low RPM combination that should at least make the car more fun to drive. The questions I have pertain to the quench, degreeing the cam and vortec head modifications.

With the pistons .021 in the hole, and a .028" head gasket, I would think this is too much quench which can be resolved easily with a thinner head gasket. Is there any problems running the .015" head gasket on a deck that hasn't been machined flat? I would think it should be fine with the thin rubber layer around the gasket but I have heard you want to use a thicker head gasket if you are reusing heads or blocks that aren't recently machined.

Do I install this cam straight up?

Last but not least...
Rumor is these newer Mexican Vortec heads don't flow like the old 062's or 906's but do have thicker decks that are less prone to cracking. Since Vortec heads have hit the market people have tried to make them flow better with sometimes bad results. What does the current way of thinking say about doing some work to these? I do have enough money to send these to a machine shop to get a good valve job and maybe some bowl work and milling done to help maximize the set up.

Again I know I have been all over the place with this deal and I appreciate all the input I have gotten. I know most of the guys here are good guys and I just want yall to know I do appreciate the help. But this is for sure the final iteration of this project, for now. Maybe down the road I can get that vintage build done.

I suppose the question to be asked is, at this power level, can you get want you want with what you have?
A tenth in quench given the risk/reward ratio of an undecked block may not be worth it. If you're comfortable in that the shim isn't going to fail, then go for it. There's nothing to lose and some benefit from the tighter quench but my understanding of that is that among other things, it provides a hedge against detonation. At less than 10:1, is that an issue? But the shim gasket is obviously a concern for some.

If you have the means to move the ICL around, and it makes sense from a compression point of view (as in an earlier IVC to boost the DCR), then why not? That's what I did in my latest 350 although I was admonished by some here because it was more of a crutch for too low a CR.

As for the Vortecs, to me their real value is what they offer in stock form. 350-375 HP is doable.

Anyway, that's my two cents to get this thread back on track.

[rfoll]

One of the benefits of the Vortec head is the excellent swirl characteristics. I would think it would reduce the need for a really tight quench. If you are going to deck the block anyway, the increase in compression is worth the effort. I have a flat top 350 with Vortec heads in my car now. piston is .025" in the hole with the .028" gasket. Static compression is 9.63. My cam is 10 degrees less than your xe 262. It runs very good on regular fuel and I have never heard it ping.

[skinny z]

One of the benefits of the Vortec head is the excellent swirl characteristics. I would think it would reduce the need for a really tight quench. If you are going to deck the block anyway, the increase in compression is worth the effort. I have a flat top 350 with Vortec heads in my car now. piston is .025" in the hole with the .028" gasket. Static compression is 9.63. My cam is 10 degrees less than your xe 262. It runs very good on regular fuel and I have never heard it ping.

Have you calculated what the DCR is for that combination? While DCR is dissed by many, I find that for a given format, such as a Vortec headed 350, it has some value. That you run on regular grade fuel is something that's come up in another thread and the running compression was a question of note.

[68maliblue]

Octane requirement is going to depend on a lot of factors such as ambient air temp, coolant temp, as well as compression ratio. FWIW I just recently did a similar build - 350 bored .030 over, Vortec heads, 9.6:1 compression and Howards flat tappet cam 215 int/225 exh on 110 LSA. Runs very good but I'm dealing with 100 deg ambient air temps so I've been feeding it 91. Seems to be happy so far on 91 with a 180 deg thermostat and 185-190 deg coolant temps.