Yes, that was exactly the sentiment I was very excited to light the roads but it was the contrary. The worse part was the lack of communication and telling me after I questioned the parts what I needed versus explaining to me my options were or could've been..... lesson learned!

 

Thank you for your reply.
The car is a weekend warrior and isnt being driven daily and no I dont intend to race it at all, I only take it out in and around town and down the countryside for some spirited weekend driving. Im not sure of the gearing in it. My expectations as I explained to the shop were to have reliable power gains above the stock ZZ4 CAM that still provides a gnarly sound (all reviews and advice directed me to Lunati Voodoo) as well as upgrading all other support parts for better performance and longevity than the stock factory setup came with. I do think the shop took the easy way out in my instance as I just put my trust in them with my wish list.

 

Even if they installed the requested cam you would not be happy with it. It clearly states a minimum of 3.42 rear gears and the stock gears on your 81 are 2.72.
https://www.summitracing.com/parts/l...20712#overview

 

Best of luck getting it resolved.
Make sure you tell them it was their choice, not yours, and they should have checked with you.
Not checking is their problem.
And with your driving style noted, I would not go 230 dur, stick with a 224 or so. Lots to choose from.
It's big enough for the way you want to drive it.

But NOT a 107 LC. 110LC or so.

 

thank you, that will be the premise of my discussion with the shop. What would be a recommendation on cam selection in this case?.

 

A cam compatible with a 2.72 rear gear, if it exists.

 

I agree with the can issue, That IS the wrong cam for what you have, no doubt. If you want much better trq out of the bottom, that cam has to go and change the rear gear and come up a bit. A 3.31-3.54 range would be better with a four speed, but it also depends on how you want to cruise as well in 4th. I would have the shop make it right and can't believe they didn't notify you on what they were going to do, before they did it to get your approval. Like mentioned, the Voodoo cam would have been better, but still not good for what you have. GL and post up how it goes.

 

If you truly have the 2.72 rear gears, the ZZ4 cam that you have is great.

First: Verify the rear gears, just count tire and driveshaft spins
2nd: If 2.72s you need more gear. Those airplane gears are barely acceptable for a stock cam. If 272s, I'll bet your ZZ cam was no stronger till you got past 30mph, then it took off. And would rev to 60+ More cam now is just going to turn it into a slug. Decide if you want 3:55s or a Tremec O.D., or both.
3rd: Decide if you need a new cam then. A 224 dur and a TKX would make it rock-n-roll! Guaranteed! Your Voodoo if you want rowdy!

 

Ok one thing you should do is download a Vehicle Information Kit for your car from GM:
https://www.gm.com/heritage/archive/...formation-kits

The GM archives say they only built some 5700 81s with 4 speed manuals. So you have a pretty rare and cool car!
But in those days that does not mean GM optimized it to run terrific.
I am glad you upgraded the 190HP LM1.
Your oem 4 speed is rather unique with a 2.88 ist gear, that is deep!.
But all the 49 state-only 4 speeds came with a OEM 2.72 rear gear.
That's long!. That is only 7.88 overall gear in 1st and you want near 10.0 to feel strong.
Here is another way to verify that gearing, you would not hit 6000 rpm until 61-61 mph. 5000 rpm at 52.
60 mph top gear cruise at 2000.

But the stock LM1 cam is very mild at low rpm, and at least tolerable with that gear.
The ZZ4 should not have lost much below 30. And pulled much better after that right?

Rule #1 in modifying your drivetrain is "It is the entire combo that counts"

3.55s would work really well with that setup. Either LM1, ZZ4 or Voodoo. Not Thumper.
Really strong around town. 30% more than you have now.
Under 30 will feel so much stronger, it'll be hard to compare.

But highway cruising will be...different,,, and slower.
Your current 272s would likely be 2000 rpm at 60.
The 355s would be 2600 at 60.
If that is OK you would not need the TKX. That would help the cruise but do nothing for 1st with that trans you have. 1st gears are the same.
The mild .81 OD TKX pulls you back down to 2100 at cruise. That is the combo that gives you a strong 1st gear, and the same cruise that you have now.

Then we will talk cams. The ZZ4 is absolutely as big as I would go if you have to keep those 272 highway gears.

So you have now entered the money pit, my friend.
I am sorry you got the cam first, even the Voodoo one. But the Thumper...I don't know what to say.
Triple shame on them for picking that cam with 272s.

Change the cam to where you want it to be long term, then decide on the gearing.
We can help you pick a 224 dur cam, but it is still not going to like the present gearing.
355s!

Those and a 224 or Voodoo will rock!

What do you think you want to do?

 

The GM LT4 Hot Cam could be a terrific choice for you: And it is still around:

"LT4 HOT cam pn#24502586 279/287; duration at .050" tappet lift (intake/exhaust) is 218/228 1.6 rocker ratio (intake/exhaust) is 525/525. Valve lash is zero/zero and lobe centerline is 112 degrees."

The ZZ4 engine has good compression and good heads, and this cam adds near 45HP (to 400) and an extra 1000 rpm. Nice chop, and still respectable mpg for cruising.
You have very good heads, so you do not need big duration to run great.

 

Here are two Howards Roller cam choices.
I would not go any bigger than the 2nd one, and that one will rip!
But both of them really need 355s! Especially the 2nd one. The first one might tolerate 272s.

219 dur This one is real close to the GM Hot Cam

225 dur

Maybe you can make a deal with the shop to go with a cam like this (their labor) and you will also do the 355s?????

That's the best I can come up with to help you.

 

Any person who owns and builds SBC's with roller cams understands that you can run 4 degrees more @.050 duration than a flat tappet cam and create more TQ and vacuum.

The L82 cam is 222/222 and very mild.

So adding 4 or more degrees is the correct way to understand roller cams and using the same lobe center angle

In your zz4 case, find out what you cam specs are and add 4 degrees and it will have more power at all present rpms

 

Thank you Leigh!. This was very helpful in my endeavor.

 

Thank you Leigh!. This was very helpful in my endeavor.