So I am building a street/strip carbureted 383 that is going into a 1995 4-door Chevy Tahoe that is set to be a drag truck. I'm looking to hopefully get into the 12s or at least low 13s ET range on a budget build. Probably hunting for 420 - 450 horse and a good amount of torque to get the 4,000+ lbs. cow moving. Want to run on pump gas, plan on getting a cast crank rotating kit with +12cc dish hyperutectic pistons to keep compression down a bit.

So, I got a decent set of Vortec heads and I want to know what would be the best cam to mate up with these to get what I'm looking for. I'm thinking I would like to keep it flat tappet hydraulic (mainly for budget reasons) unless a good amount of you really suggest I should go with roller or some other valvetrain setup. I have poked around a few threads in here and found a good amount of people using the Comp Cams XE274 getting in the low 12s, granted they are running F-bodies that are considerably lighter than my truck. Would that be the best route or are their better options out there for me?

I also am open to suggestions/critiques of my build strategy too. I know it is more worth while to invest in topend before anything else, and forged rotating kit is a good investment for future changes, but I don't plan to do much much different with this engine (as far as super charging and nitrous is concerned) and I would really like to have it ready to go in by this summer. The 350 block I got is a 4-bolt out of a 1993 Silverado 2500 and it's already with my machinist and bored .030 over waiting for a rotating kit so it can be clearanced and honed. Summit has a great intake deal going on right now with the Holley 770cfm street avenger and the GMPP Eliminator Vortec single plane intake manifold that I was eye-balling... but I hear an Edelbrock Performer RPM airgap is really the way to go. So what do you guys think?

 

Something with 8-10* more exhaust duration (compared to intake @ .050") would be a good idea. Vortec heads don't flow as well on the exhaust side as they do on the intake side, so they really respond well to extra duration on the exhaust lobe.

I like my XE274, but I think if you are building an engine from the ground up, then go with a roller cam - you'll be happier in the long run. A '93 350 block should be a roller block, so you don't even need the expensive retro-fit stuff. Alot of the LTx guys with heavily built motors like the GM #847 cam in the 383ci engines. Its a pretty healthy cam and a good choice for heads like the LT1 or Vortecs (they are pretty similar).

 

whats the idle like on the ex274? have a sound clip by chance?

 

Where could I get my hands on that GM cam? I found a really nice cam kit on Summit for the Comp Cams XR282HR-10 with pretty much everything I need except pushrods, plate, and rocker arms:
http://store.summitracing.com/partde...8&autoview=sku

Would that be a good investment? It's pricey but everyone keeps saying to go with roller. I want to make sure I can keep decent vacuum to run brakes and all that... but then again I plan on going to the hydroboost system so maybe it's not that big of a deal?

 

You're still going to be up over 10.3:1, too much for the RamJet cam.

 

What's the ramjet cam? That the GM 847 that Air_Adam mentioned?

 

It sounds great, but its not really rough or anything. Its got a very noticeable lope, but not too raunchy. Look up 'XE274 chevy 350' on YouTube and you'll find lots of examples of it.

EDIT - heres a vid of an old Nova with a 350/XE274. Sounds alot like my Camaro
http://www.youtube.com/watch?v=0B-wQKSYV2E

I doubt thats the 'stock' cam for that engine... its a pretty radical cam for a drop-in crate engine. Its a really nice cam though!