dopgx3

Hello all,

I'm collecting parts to boost the power of my anemic 350. This is my first post but I have read through several posts here over past month or so, finding tons of great info for a few things I've been trying to work through on my car.

Well, at this point, I've narrowed down my cam choice to 2 Lunati cams:

Voodoo 10420704 used by Coppercutlass:
Advertised Duration (Int/Exh): 276/284
Duration @ .050 (Int/Exh): 233/241
Gross Valve Lift (Int/Exh): .522/.539
LSA/ICL: 110/106

Streetmaster 10420313 used by 80 Rocket:
Advertised Duration (Int/Exh): 276/286
Duration @ .050 (Int/Exh): 221/230
Gross Valve Lift (Int/Exh): .485/.485
LSA/ICL: 112/106

Here's my target end state for the engine:
stock bottom end 350 #395558-2 (overbore unknown)
stock pistons, dish cc unknown. (I know compression won't be anywhere close to 10:1 but will not do a complete rebuild anytime soon)
#5 heads with 2.07 int, 1.63 exh valves (likely no porting, open to valve size recommendations)
Won't be welding the exhaust devider and probably won't bother filling the crossover either.
Cometic head gaskets (4.125" bore, .027" thickness to help compression)
1.6 Roller Rockers
1-3/4" long tube headers w/2.5" exhaust to the rear
Performer RPM intake (likely with 1" spacer)
Fitech EFI
Mallory HyFire 6a
3.73 gears, 26" tire
200-4R with min 2800 stall

I've been impressed with the results Coppercutlass and 80 Rocket have had with their relatively basic builds and I'm hoping for similar results. This is a daily
driver car so I'm leaning to the Streetmaster but after hearing a vid of Coppercutlass car, the Voodoo seems like it'll be fine in a driver (not race cam radical)
and produces enough vac for power breaks.

So now I look to the collective to help me decide between the 2 based on future setup. What are your thoughts?

Fun71

With those unknowns, your compression could be as low as 7.5:1 if you have dog dish replacement cast pistons that are short on compression height. If that is the case, those cams will totally kill the low end and make the car miserable to drive.

Do you know if they are actually factory pistons or are they aftermarket replacements?
If factory, do you know what year the engine is? That will help determine the possible piston dish volumes.

coppercutlass

I may add The cam i have produces just enough vacuum for power brakes in my case . Im going to manual brakes later this summer.

It does not help that my engine is tired and its starting to smoke. I built that engine almost 5 years ago and it was built really loose from the get go. Im sure thats been affecting my vacuum as its progressively gotten worse but oddly the car has gotten faster lol.

You really need atleast 9.5 to 1 + compression.

gs72

I think maybe you have gotten faster. Lol

svnt442

It's because you are in Illinois and the car is "shedding" (rust)...lol.

olds 307 and 403

Unless have early high compression pistons, you will have high 8 to 1 compression at best. I had milled #6 head with 62 to 64cc chambers, verified by me with fresh 2.07"/1.56" valve job with a bowl hog to open the bowls. With the factory 76 14cc pistons .025" to .030" in the hole and .028" Rocket Racing head gaskets, it puts me at 9 to 1 compression. I went with a custom cam from Cutlassefi, just getting it running right now.

Kennybill

Do you know for sure if your #5 heads are large valved 2.07"? To many unknown variables to go with either of these cams, JMO. Also (jmo) it's better to be under cammed and under carburetor than over. The factory camshafts are decent till 4500 rpms. I would put a RV Comp Cams such as 262 H, I think. I had the 0.456/0.456 in a low compression 350 with 3.73 gears and it ran good.

coppercutlass

I ran 13.8's with the 260h cam. 3.73 gears. It was a 73 350 with 72 heads. All pretty much stock on tje heads and block. Keep in mind my car weighed 3250 when it was all steel. Should be 3100 now with the fat trimming i did.

dopgx3

First, I really appreciate all the replies...

based on the block number it would be a 68-70 model year. As for the valve sizes, I should've clarified that I will be having the heads built with those valve sizes. I like the idea of milling the head to reduce chamber size a little but I jus worry that I'll have to milk the intake too which is something I really don't want to do.

Unfortunately I can't check the pistons to see if they are aftermarket or look deep. Maybe I can get a scope and look inside the spark plug hole to see what I can see. That's probably the biggest unknown for me at the moment.

dopgx3

That statement alone makes me think I should pass on the voodoo cam for a daily.

marcar1993

^I have more cam than that (in a 403) and still have power brakes, and I too am right on the edge of power brakes without a vacuum can... However I have 10:1 compression to use it.
You need a smaller cam with the setup you have. A cam is only as good as the rest of the combo. Before you do anything else, you need to MEASURE EVERYTHING and get a real measured compression ratio, not a geusstimate.

dopgx3

yeah, I guess I'm going to have to make the cam the last part to order after I get a chance to see what kind of pistons I'm dealing with. This all seemed simpler when working with SBCs years ago. And I'm trying real hard to not follow the LS herd.

coppercutlass

^ alot of guys have ran bigger cams. Like i said my engine is tired and you loose vacuum through worn out rings. The lunati cam i have is the second biggest they make in hyd.

Now i ran a howards 512/512 cam on a 110 lsa i wanna say 224/234 duration and it worked great.

I have that cam BTW and new lifters. Pay for shipping and its yours.

The cam is used but great wear pattern and new lifters . would have to get broken in again.

In the video you will see. You can see the blow by coming out of the breaters lol. Thats the same short block and heads im running LOL. All i did was change cam. This video was shot 4 years ago 1 year after i got it all together.

Fun71

Wrong, that's some misinformation from the Olds FAQ. The 395558 2 block was used from 1968 up to 1976, and there were pistons with 6cc, 14cc, and 24 cc dishes, depending upon the year and application. You would need to look at the VIN pad on the block to determine the year of manufacture.

dopgx3

Just shipping? That's a sweet deal! I'll PM you later. If nothing else I can hang onto it for a better build. Now the bad news.... Turns out Fun71 not only educated me but also busted my bubble because I checked the stamped ID and it looks like it's a 76 block (36xxxxxxxx) which I'm guessing very likely has the deep dish pistons...which also explains why it's so anemic in the first place. Now I need to figure out what I want to do next before anymore thought goes into a cam for the current block.

Fun71

The big 24cc dishes were used in 71-72. The 73-76 engines used 14cc dish pistons, which can give decent compression when used with heads that have a smaller chamber volume than the #8 heads that come with those engines.

coppercutlass

Like fun 71 said you can used 7A/7/6/5 heads on the 73-76 short blocks and with a thin gasket and milling the head you can get 9 to 1 compression.

My little 350 that ran 13.8's in the quarter used a stock 73 short block ( freshened up ) and freshend up 72 7A heads with a 260 h cam , edelbrock performer intake. thats about it. rockers/ puhrods/ all pretty much stock or stock replacement.

dopgx3

oh that's right! I remember reading that somewhere...ok then all is not lost yet. I have #7 heads now but I don't know what all is inside currently that's holding it back. I just know what I'd like to put in it. I guess I'm gonna have to buy a new tool to find out for sure...inspection camera I'll see if I can get some pics and post em up as soon as I can.

olds 307 and 403

I used a 76 block which if it is original, 9 to 1, will require a slight head mill, 1cc for Olds is a .006" cut. Pull the heads, then you know for sure what pistons are in it.

dopgx3

good info on the cut! gives me an idea on what to thanks.

Coppercutlass, I've been giving this some thought and I hate to be "that guy" but I'm going to have to pass on the generous cam offer. going over the responses from this thread and others, I think the right conclusion is that the Voodoo and Howards cams will be more cam than i would ever utilize. Plus I won't be able to get to a complete build anytime soon to put the right pistons and get the ideal compression necessary for those cams.

The Streetmaster or something similar is probably the more suitable. But I still need to find out what pistons I have before committing to anything.