Hello all!
I am shopping around for a retro roller hydraulic cam for my .40 over 383 mild stroker build.
I have a 74 vette, with auto trans (TH400), and I THINK a 3.08 rear ratio.
I don’t know EXACTLY what it is because I never planned on a rebuild and I removed the drive shaft before I took the time to see what the axle ratio was.

This whole thing started as a starter issue, caused by a bad battery-to-starter cable, and had to remove trans to replace it. Then, as I ventured down the rabbit hole, I decided to pull the engine as EVERYTHING was leaking on it and replace a few gaskets. Come to find out, as I pulled the oil pan to replace the gasket and the rear main seal, the oil pickup was resting peacefully in the bottom of the pan and upon further inspection, the main and rod bearings were just about shot.
So here we are…..
The block is from an 86 3/4 ton truck with 4-bolt mains and was already bored .030 by a PO.
I had to bore it to 4.040 to clean it up, and the used scat crank I purchased from a friend has been ground as well.
I went with Speed Pro 12cc dished hyper pistons and 5.7 rods and my machine shop will be balancing the rotating assy this week.
My vortec 062 heads have been magnafluxed and shaved for straightness (flatness?) Also had a 3-angle valve job, screw in studs and LT-1 Z28 valve springs installed.
I have an Edelbrock RPM Air Gap manifold along with a Holley 650 carb.
I plan on purchasing a 2500 stall torque converter for my TH400 trans, unless my cam decision needs a different stall. TBD?

My calculations put me right at 9.9:1 CR, and I plan to run 93 pump gas.
This will be a fun weekend cruiser but will not see any track time. Maybe a trip to the dyno, and definitely some spirited driving on our mountain roads. More on that later.
I have done extensive research on our forums, and have narrowed it down to either a Howards or Lunati Voodoo cam. (Still open to suggestions, though).
I talked to a very knowledgeable guy at Howards, and he suggested the 110255-12S retro roller cam with 510/530 lift, 231/235 duration and 112 LSA.
Just wanted to see if anyone else is running this cam or has personal experience with it? Other suggestions?
I want this to have a pretty decent idle, mild street manners and not too much lope. Something my wife can enjoy with me so she doesn’t make me live in it 😂.
Haven’t decided whether I’ll be running headers or 2.5” rams horn exh manifolds.
Any expertise is greatly appreciated.

 

You’ll need a valve spring swap to run that Howard’s cam. If you’re going to change springs and like Howard’s, what are your thoughts on this cam? 110325-10. If you run 1.6 rockers the effective lift goes to .560 and .565, which should make it a nice torquey engine. Talking with Scat and Eagle, if you stay under .550 lift based on 1.5 rockers they say you don’t necessary need a small base circle cam with their 383 kits. But obviously your machine shop will need to check clearances.

 

Thanks JC,
Im ok with swapping valve springs for the right cam if necessary.
The Howards 110325-110 sounds nice and torquey, and I will definitely look into that one.
I guess I’m kinda hung up whether to go with a rough idling cam or a fair idle.
I want mild street manners, without too much lope, but on the other hand, if I wanted a boring car I’d buy a Prius.
Looking for an old school vibe without going overboard plus I really want to keep good vacuum without having to shell out more money for secondary vacuum pumps.
My machinist said it was safer to go with a small base circle cam to prevent clearance issues with the rods I provided.
Although I have been researching quite a bit for this build, there’s still so much I don’t comprehend. I’m a carpenter by trade but constantly trying to learn more about mechanicing, so please excuse my ignorance on some aspects of the build. I’m not sure whether to go with 1.5 or 1.6 rockers, but my machinist advised against roller tip rockers.
Just an overwhelming number of choices which all affect a slew of other choices….

 

Just a heads up. With all the rotating assembly parts coming from different sources, it would be money well spent to have it all balanced. It will not only make a much smoother running engine, it may save you a lot of grief chasing a vibration later.

 

I like the 110325-10 suggested above......I am using this exact cam in an engine soon (357ci)
I wouldn't go 1.6 on the rocker simply because the Vortec head doesn't flow any better at that lift.....opening the valve further would not achieve much.....and you need to watch retainer to boss even if the heads were cut for it. Call PAC for a spring or.....find the right spec in the Howards catalog. A beehive would work here as the lift is not too severe.......
This is a strong running cam and has a lot of midrange.....right where the Vortec heads do well......should be all done by about 5700 rpm.....

Jebby

 

I agree 100%. My machine shop is supposedly starting the balancing this week. I say “supposedly” because they’re short handed and have tons of other projects going on besides mine.
No rush, though, because I still have plenty to do on the re-wiring, steering, front suspension that would be easier to accomplish while the engines out.

 

Thank you for the confirmation Jebby on the 110325-10. Sounds like a great all around cam. Hopefully that grind is not on National back order….

As for the springs, I will research the beehive further and likely go with those if we won’t have any clearance issues.

The rockers on the other hand….
I have a new set of stamped roller tip self aligning rockers that I had planned to use, but my machinist advised against the roller tip stating that they wear out valve tips too fast, my current valve tips are too short anyways, and suggested using roller pivot aluminum rockers instead and installing pushrod guide plates to keep things lined up (which would require further machining on the heads?)

If I upgrade to the beehives anyways, would it still be best to use aluminum rockers and guide plates in lieu of self aligning stamped steel rockers?


Thank you for your help!

 

Use a self aligning roller tip rocker or full roller.......they are made specifically for those heads.....
https://www.summitracing.com/parts/cca-1417-16
Or full roller...these fit under centerbolt covers too.....
https://www.summitracing.com/parts/cca-1617-16

Whatever you pick...make sure you use short poly-locs.

As for roller tips causing a valve wear issue.....how come they are ok an a full roller then? Total bullshit.

Jebby

 

I have a 383 with Vortec heads in my 77. I've been using the Comp roller tip rockers that Jebby recommends (PN 1416-16) for years. Thousands of street miles and hundreds of 1/4 mile passes with no problems. I am not using poly locks and they do fit under the stock center bolt valve covers. My hyd roller cam has .535/.550 lift.

 

If your willing to do a spring swap, maybe a little more head work to take advantage of that additional lift…. 👍🏼

Or something to think about in the future if you get bored with the power…

 

As always, great pointers from Jebby and BKBroiler and many other super knowledgeable guys on CF.
I think I’m zeroing in on some decisions I’ve been mulling over and putting off for some time now.
I’ll keep you guys posted on my progress, however slow it has been going.
Rome wasn’t built overnight. Lol
Im all ears if anyone else has any pointers or details I may be overlooking.
Thanks again to all!

 

I have considered porting the heads, but if I pour any more $$ into them I’ll be into aluminum head territory….lol
Hindsight is 20/20.
But, since you mentioned it and I’m already vested in these vortecs, what would you recommend?

 

On the subject of rocker arms, one thing I forgot to mention - just fyi, 1.6 rockers on Vortec heads require enlargement of the holes where the pushrods pass through. I had 1.6 roller tip rockers on mine for a while when I had a flat tappet cam in there.

 

My ZZ383 GM crate motor came with a .509 .528 lift 222/230 @.50 dur. 107/117 CL 1.5 rockers
Supposed to give 430hp
I imagine they have the facility to do alot of test/dynoing

Semper Fi

 

Thank you for the heads up. I was not aware of that so I will be sure to stay with 1.5 rockers.

 

Semper Fi, brother!
In hindsight, I should’ve gone with that same ZZ383 crate engine you got, considering what $$ I’ll have in mine by the time all is said and done, not to mention time savings and a warranty to boot.
I hope to end up close to those numbers if at all possible. What head combo came on the ZZ383?

 

 

GM branded alum vortec with beehive springs, roller 1.5 rockers, 62cc, fast burn, 2.0/1.55 valves
I have no idea who makes them, but its prob easy to find out

 

sounds like a nice setup!
Thanks for the info

 

thank you for sharing the video. It was very informative and David vizard is a fantastic teacher.