TRN4L

I will start by saying I am a relative novice, so please bear with me. This is my first corvette. I bout a 1979 C3 with a Vortec V8. I'm slowly bringing the car back to life, but Im curious to know what would be a good cam? What else can I do to improve performance? I've been searching so I'm a little familiar but I wanted to ask people with more knowledge than me.

mikep3

Can you tell us if your Vortec Engine is a crate motor (new engine) or an L48 with new heads. Would also help to know the transmission and rear end ratio.
Pictures always helps.

jackson

ditto ... and complete your profile to include an approximate geographic location ... other questions will likely follow ... you location may help get you a better reply ... no we don't want your vin, tag # or street address.

TRN4L

I'm pretty sure the engine and trans are out of a truck. I'll have to look at the codes on the motor to find out for sure right? IDK the rear end ratio. I think its the stock rear end if that helps. When I got the car it was a complete cluster **** in terms of how the motor and trans was installed. I'm working hard to get it all straightened out.

jackson

suggest you Verify it's Vortec or not. Not all center-bolt valve covers are Vortec. But all Vortec with w/ OE auto trans came w/ computer-controlled trans. Start with Both block's ID stamp pad AND casting number. ALSO pull a valve cover; find & record head casting number. AFAIK, true iron GM Vortec head c/n either 10239906 OR 12558062.

all this to help determine chamber size (compression ratio) and if you can easily use a roller cam.

If it has a carb & intake, then ALSO get the numbers off the intake manifold.

reply this thread w/ your numbers.

TRN4L

The block has been painted so the numbers on the block are hard to see. I'm going to take a wire brush to it tomorrow. I also took a good look and figured out the intake is an edelbrock performer. the carb is also a 4barrel edelbrock. I dont know how i never noticed the edelbrock logos on them. smh. Idk how to find out what model the carb is. any ideas? Idk if it helps but there is also a Holley electric fuel pump. I will have the block and head numbers tomorrow I hope. Thanks for all the help!

jackson

look for a raised Part Number on the edelbrock intake ... probably 4 digits. post here

TRN4L

14093638 is the number I got from the motor. I looked up the carb already. It was a 600cfm carb.

worship79

If it indeed is a L48 with vortec heads you might want to consider reading the Chevy Highperformance Goodwrench quest! http://www.chevyhiperformance.com/te...ild/index.html

jackson

get the head & intake casting #'s.

at this point it ain't looking like a Vortec.

14093638 Probably ... Probably 87-95 throttle body inj motor. May or May Not have roller cam

get the head & intake casting #'s & post em.

Rotonda

A quick way to check. How many bolts per side are holding your manifold to the head? If 6 per side (total 12), almost certainly NOT a Vortec head. If 4 per side (total 8), probably a Vortec head/manifold.

The block is important. If a truck block, you will need a roller cam. If the original L48, you will need a flat tappet. The roller cam will both offer more potential and will avoid the all to common wiping out a flat tappet lobe.

couperdecar

My '79 L-48 was upgraded to Vortec heads and the cam I added was a Cam Dynamics 272 H10. .454 lift. Recommended 2000 - 5000 rpm. Lots of torque. Cam sounded real nice. The actual spec sheet is copied in my 'album'. I was quite happy with it until I came across a 383 short block for $1600. Couldn't turn that down. I'm still using the vortec heads.

TedH

What intake manifold did you use to fit under your stock hood on the Vortec-headed engine? Vortec head and intake manifold height have been a 'blocker' to my upgrading my top end to vortec (won't fit under my stock L48 hood on '80 C3).

Funny, your cam dynamics grind is VERY similar to my Crane Energizer 272 H10 grind (.454/.454). Probably identical. VERY peppy with my combo (non-Vortec) by the way.

vanice

This is my 77 355 vortec headed engine with a ZZ4 cam. The manifold is GMPP 12496570 it will accept either square or spreadbore. I am running a quardajet and the air cleaner is a drop base and fits under a stock hood. On a 80-82 you can't use a 3 inch element 2 1/2 should clear. Earlier hoods had more clearence.

TedH

VERY nice!!! Thanks for sharing. I think I've decided on my winter project

jackson

also consider Pro Products 52007 ... made for spreadbore but also fits square ... shorter than edelbrock (EB makes the vortec intakes for GMPP). It ain't only the height ... just as important is the angle ... think of a ~14" air cleaner lid at that angle.

*Cast Iron c/n 3973460 (OE '71 L48) F = 2.69” R = 4.375” avg=3.53”
35 degrees down in front

*Weiand alum. p/n 8004 F = 3.50” R = 4” avg 3.75”
11 degrees down in front

*Edelbrock p/n 2101 F(aka A) = 3.50 R (aka B)= 4.60 avg=4.05”
22 degrees down in front

*vortec EB 2116 F=3.87" R=5.28" AVG= 4.575"

*vortec PP 52007 F = 3.60", R = 4.90", AVG = 4.25"

jackson

TedH
You might also consider using L98 aka ZZ4 aluminum heads ... their 58cc chambers great match to L48 dished pistons. Uses centerbolt valve covers & self-aligning rocker arms but "standard" intake manifold pattern ... even your OE L48 intake will fit L98/ZZ4 heads ... new can be had for $1000/pr or less ... plenty good used ones around for much less. Depending on gasket, will bump OE L48 to about 9.7 - 10:1 scr ... will pop w/ your cam.

Yellow74c3

I put a set of Vortec heads on my 74 with stock hood and was able to fit a Edelbrock RPM intake and a 750 Holley carb by using a drop base air cleaner, I cut the base out of the factory dual snorkel top section and attached it to the drop base.....keeping the stock look....I am using one of the new Thumper Comp Cams.....combination sounds good, haven't hit the road yet, still working on body and interior.....Fred

springer89

Yellow74c3- could you post a few pics of your ac setup? thanks.

Scottd

DO YOUR RESEARCH! Vortec heads will only take so much lift without modification to the valves. By the time I finished machining my heads and buying special springs, I would have been better off buying a set of aftermarket heads (that would have fit a bigger cam to begin with) . I will say Im VERY happy with the Vortecs. The only specific I remember on my Cam was .469, but Ill be damned what spec that was. Ill look up the Comp part number later....do some poking around online, it doesnt take much searching to find what the heads will support. ( I do remember I had all the numbers I needed in one evening)