GM4EVA

Hi everyone!

I'm a new guy on this forum looking for some advice from the experienced cam guys out there. I own a 1977 vette with stock L48 motor (needs to go).
I'm swapping it out and building a 350 40 over with Speed Pro H345NP
-5cc flat tops. At the moment I'm putting on a set of 64 cc 492 casting(old Lt1 370hp) dubble humps with pocket porting/bowl blending, (budjet issue). I'll be running crane energizer 1.5 roller rockers, Edelbrock Performer RPM manifold, 600 cfm Carter AFB, 1 5/8 full length headers, 2 1/2 dual exhaust, 3.08 gears and a 350 trans w/2000 stall converter.
Using a CR calculator I get about 10.3:1 CR,(to much for the heads??) while Jegs reports a 9.35:1 with these pistons?? I,ll be running on pump gas, 98 (RON) or 93 (AKI) for you in the US.

I'm pretty much down to 2 cams, but would like some insight from you that have actually run a similar setup. Comp cams suggested using their 274, which IMO is to big for my combo. From what I've picked up from different forums, the 262 seems like a good choice. Also the 268 seems appealing, but it looks like the 262 can outperform it.

Lunati recomends their 60102 which is quite similar to the Comp 262, but with a lsa of 112 instead of 110. How will they differ?

I live in Finland and we have a long snowy winter so I only use the car for a period of about 4-5 mo. out of the year
My goal is to build a street motor (not a daily driver) with low and mid range torque w/ 350-400 hp. A noticeable lope to the idle and a sweet exhaust note would be nice, but not compromising the torque/power.
I know my heads and gears could be better, but I will address those issues at a later time!(with a heavier wallet) Please take into consideration, that I already have all of the above parts with machine work done.
BTW, I already had an Edelbrock 7102 cam kit (new), I ditched the cam but saved the lifters. Any reason not to use them in this setup?

Any advice/opinions and other cam choices will be deeply appreciated

Thanks,
-S.P

GeorgeS

Welcome to the forum SP! I am no pro at this so please wait for the "tech" folks to chime in. That 274 is not too big for your set-up. I have Crane Z274 in my 327 and it runs great.

GM4EVA

How is that Z274 doing as far as vacuum goes? The Comp 274 only makes about 11" Hg at 800 RPM and 14" at 1000.
Not sure thats enough for power brakes??

glen242

I am running a CC XE274H cam on my stroker. 13" vacuum @ about 900 rpm idle.

Brakes are fine.

Sho'nuff

IMO..u need more carb!

jackson

use your NEW lifters with ANY Hyd Flat Tap cam.

jeg's 9.3 wrong ... YOUR scr calc is correct ... with correct quench height, scr will be about 10.3:1 ... so, Iron head 10.3:1 sbc will require good octane gas

sealed power aka speed pro cam p/n CS1062R is reasonable compromise between 262&268

220*/231*, 468"/480"

73, Dark Blue 454

Tough call. When do you intend to swap out the 3.08's, and to what ratio?

Also, I'm done with flat-tappit cams as are many in the hobby. For a bit more money, I'd go roller which will almost eliminate potential problems of wiped lobe(s), and a roller will build a bit more HP and maintain good vacuum.

GeorgeS

I have 16" No problem with the lights.

68/BB

You asked about the difference between 110 lsa and 112. Basically the 110 will give you more chop in the idle. It may bleed off more compression also but if you are going to be around 10 to 1 that shouldn't be a problem. I like the 268 for you. Good street manners and realistically you're going to want your power at a fairly low rpm, based on what you have described as your application. However, take what I say with caution as I am not an expert and I'm sure there are some on here who will chime in with much more engine building experience than I have. But I have built a handful and I was always happy with my outcome.

GM4EVA

I'll most likely try 3.55's but I would also like to swap out the 350 for a 700R4. With this I could go even higher. The car will see some hwy, so a screamer is not what I am aiming for...
Since I don't have the cam yet, I just might go for the roller. Realy would like to, but again, budjet issues... For now, I'll just stick with this setup and do the build to see just how satisfied I am with the outcome. Any way you look at it, it's still a big step up from about 180hp. LOL.
Thanks to all for the input till now. Some of the gurus could chime in though!

GM4EVA

BTW...If I ever get anything neer 400hp, what can I expect to blow as far as the drive train goes? I believe the trany is first to go.(a good reason to change it..) How about the half shafts and so on? Should at least upgrade the uni. joints to solid ones right? any other advice??

And just to clue you in, I live in a country with just over 5 mil. people, and sure, we got chevys, but nothing like in the US. So parts, esp. used, are sparce, not to mention EXPENSIVE...
I envy you in the US of A!!!

73, Dark Blue 454

Generally, the basic Vette drivetrain can handle around 450~ flywheel HP with street tires. After that, all bets are off. What breaks first is anybody's guess. I'll guess one of the 6 factory u-joints.

And of course, with fat sticky tires, all bets are off, period.