kdgreen

Hey Guys I need some help. I am putting a 350 sbc in my 86 iroc. I have a 4 bolt main block. It is going to be 30 over. I am going to use the factory crank turned 10/10 with all new bearings, forged flat top pistons, factory rods. I have a set of 882 factory heads/a set of 441 factory heads/a set of vortech heads. I am going to use an edelbrock performer rpm intake with edelbrock 750 cfm carb with elec choke. What set of heads would you have worked to go with this combo? I hear about 20 different things from people I know but none of there stuff stays running long. Also what about the cam? I was thinking of a 280 comp cam but don't really know. This is my first engine rebuild. Man I am having so much fun tearing this car apart. Any help would be greatly appreciated.

RB83L69

If you have a set of Vortec heads (AFAIK Vortech does not make heads, only blowers), those would be the ones to use. The RPM manifold works well with them; make sure you get the specific one for Vortec heads.

There are several 280 cams from Comp. The XE280 is too much cam for those heads, as they come from the factory. The other 280s are not a good match for their flow properties. You need to stick with a cam with less than .480" of valve lift, and a bigger exhaust lobe than intake, because those heads flow much better on the intake than the exhaust side. Probably the best combination of safe and best power would be the Comp XE262. Replace the valve springs, retainers, & keepers; the stock ones are crap. You will end up with a kind of high compression ratio, so use the regular FelPro 1010 head gasket. You will need self-aligning rockers unless the heads have been set up for guide plates, which they are not from the factory.

92RSFivePointSlow

The 882's and 441's are both 76cc heads. Between the two I'd go with the older 882's, probably more potential, better material with those. What are the vortechs from, and can you get a casting number from them? If they are from a 350 then you could probably still use them with your flat tops, but you'd better do some math first. They will also require a more expensive intake manifold.
I have a comp 280H cam in my 350. What stall speed is your torque converter? That cam really needs at least a 2200rpm stall at the minumum. They dont reccomend anything less than 1000rpm above stock stall with it. It doesnt get out of it's own way with a stock converter. Idle is noticeable, I was driving it around with the idle mixture too lean and the timing advanced some, but apparently not enough. I richened up the idle and advanced my timing a little bit each pass down the track until I got the best time. At the end of the night my idle was really pronounced. It sounds real badass now. I shift it at 5500. It's a good cam if you've got heads that will give you 9.5:1 compression and a 2600rpm stall converter(these parts are in my basement waiting for me to get motivated enough). But if I were you I'd really look at the cam made by lunati that is included in the holley systemax kit. They claim 350hp at 4500rpm, and you can purchase that cam seperatly- it's in the "bracket master" series. Stupid me, thinking bigger is better, I researched that lunati cam and still bought my comp 280. I rev to the moon but only have 320hp now.

Jim85IROC

iTrader: (2)

I agree on the vortec heads. The 882s can be made to flow half decent if you **** a ton of money into them (and if they aren't cracked, which isn't likely). I don't know a thing about the 441s so I won't comment.

The vortecs are the best flowing factory small block heads that GM has ever produced. The edelbrock vortec-compatable intake manifold will cost a little more than a normal one, but the difference should be well worth the added performance.

ede

i'd use the vortec heads and trash the others. i'd buy my cam from lunati and my induction from holley and weinad.

kdgreen

Ok guys. I will go with the vortech head with new springs/valves.
What is the model # on the lunati cam? And which pistons would you use? Also which headers would you use?

92RSFivePointSlow

if you're going the route via. ede, how about you just buy the kit holley systemax kit? It comes with the holley manifold, cam, lifters, and timing chain. I know it's listed in the Jegs catalog, and in the ad it conveniently gives you the cam specs. To find the cam sold seperatly, all I did was go to my Summit book, in the "hardcore racing" section for cams, and found the lunati bracket master cams. That cam is in there, just look for the same specs.

WS6_355_TPI

Junk the 350... go 400

Jim85IROC

iTrader: (2)

Yeah, because we all have 400 blocks sitting around in our garages.

RB83L69

I would use flat-tops. TRW/Speed Pro are entirely adequate. Put new bolts in the rods.

The reason to stay under .480" valve lift is that the retainers will hit the top of the valve guides if you exceed that. This is critical; the motor will not survive if this happens; be careful.