ykf7b0

I recently spun a rod bearing in the factory numbers matching L-48 350 and ruined the crank. The engine needed .030 over bore to clean up and I've opted to go with a 383 stroker kit. I also have factory GM 1999 062 L31 Vortec heads that I will be using and will be getting the lift issues taken care of by my machinist. My 76 Vette is an a/c car with power brakes and I know I'm limited with my camshaft selection due to needing plenty of vacuum. I have headers with 2.5 inch exhaust and I wish to stay with my stock torque converter. I would like to get your recommendations on a great cam selection to go with my components.

StraubTech

.510/.510
223/235
108 LSA

Makes 11" of vacuum.

NewbVetteGuy

I could've sworn I heard a guideline to just figure out the attributes you want from your cam and use the typical SBC 350 guidelines for duration and just add 10 degrees for a 383.

Straub - any feelings on the SUPER simple guideline?


Adam

ykf7b0

I could be wrong on this but it is my understanding that the Vortec heads are a little weak on the exhaust side and this has me leaning toward a split pattern profile with more lift and duration on the exhaust side.

63mako

Don't need more lift. Vortec heads hit the wall at 520 lift. 12 degrees extra exhaust duration is plenty of split.

v2racing

The cam Chris recommended already has 12 more degrees on the exhaust side. More lift on the exhaust isn't going to gain you anything.

Mike

drwet

My 383 has 222/222 hydraulic roller cam. Plenty of vacuum and torque is good. If I were to do it over, I would probably go with a little more cam, and maybe consider split duration. I think the engine could handle it.

ykf7b0

I would go roller if I had the budget for the set up so it has to be hydraulic flat tappet.

ykf7b0

I'm forever the conservative and I'm currently looking hard at Howard's 269/279 215/225 .455 .465 with 112 LC. Again, I have a stock converter, a/c, and power brakes. What do you guys think? Too conservative????

BKbroiler

Too conservative, based on my experience. I had a flat tappet hyd cam in my 383, with 218/224 duration. I would get some detonation at part throttle going up hills etc. Switched to a roller with 225/232 duration, and no more detonation.

ykf7b0

Another choice in question is an Elgin 282/294 216/228 @ .050 .453/.480 112 LC. ???

drwet

Too conservative for an engine that size. I would be looking in the 225-230 range on the intake, and 230-240 on the exhaust. 110 LSA is about right.

ykf7b0

Another concern I have is the need for a small base circle cam if I go large. Your thoughts?

Kacyc3

go with 225ish/235ish @.050 and as much lift as you can with your heads, if you have any thoughts about adding efi later get a 112 LSA.

I have a 234/244 .489/.510 112 in my 406 with efi and it has lots of low end and pulls great to 6k here is how mine idles

drwet

I do not have a small base circle cam in mine. In fact I was unaware that small base circle cams existed back when I built my engine. I did know that I had to check the clearance between the cam and the connecting rods, which I did, but there was no problem.

cv67

Straub has already done the homework on this his recommendtaions are about as good as it gets. 215@050 will act and sound stock on a 383..you will probably wish youd have gone bigger.(will still run good though)

ykf7b0

The 11" of vacuum bothers me. I'm thinking I'll have a hard brake pedal.

C3 Stroker

11" of vacuum will be fine. I've had 9" with a previous cam/engine combo and power brakes, wipers, and headlights worked OK, no issues.

ykf7b0

Who is selling this cam for a sbc?

Buccaneer

Visit Straub Technologies... http://www.straubtechnologies.com/custom-camshafts/