350/383 First Build for 74 Nova

Hello All,
Just purchased a bone stock 1974 Nova Custom 350/TH350 it still has the stock buckets and console shifter. The car is in great shape. The only mod to it was a new radio. Anyway I am looking for advise and experience from all the gearheads out there. I have a 350 out of an early 80's pick up on my engine stand. I want to build a reliable street performance engine, to replace the tired 145,000 mile smog pumped 350. I'm not sure what HP figure I need but I want great torque through the power band (especially down low). The vehicle will cruise mostly with some trips to the drag strip for fun. It will not be my daily driver. I have a good working knowledge of engines just haven't had the money or tools to rebuild one until now. I do have a reputible machine shop in town I can go to for help and work.
Since I am rebuilding would a 383 stroker be the better way to go. I have been looking at the Comp Cams Extreme 262 cam (too rough at idle?)and a set of Dart SS heads (72cc). I already have the performer manifold and 600 cfm edelbrock carb. What are your recomendations? I would like to be in the 13's with this car. Is that too radical for a reliable cruiser? Thanks in advance for your advise. Rich


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A 383 would probably be a good choice. I would not use that line of cams though if this is your first build and you want a long time reliable engine, they work great for power but have wear issues. I would instead go with a 264Mega cam from Isky and install it 4º advanced. It'll give GREAT mid range power and that is what you want in a street cruiser. If you already have the DART heads then they'll work fine, but there are better ones out there for less money. A good set of worked over camel hump heads can out perform them and cost less. Same thing for the Performer manifold, its an OK stock replacement but an RPM is better and worth the little extra cost if you have to buy a manifold- sometimes you can score a used one in a deal too since they are really plentiful now a days. I would keep you compression around 9:1 so you can run on 87 octane with no problems. You could gain a few hp by going more radical on any/all of these things BUT you give up reliability and streetability which from the sound of it is pretty important in this build. 13 sec. 1/4's should be relatively easy as long as you have a mild stall conv. and decent gearing.

With respect to building a 383, I think it is a very good idea. The only other option would be trying to reuse the crank and rods that you already have and go with a 355. It may be worth your time to talk to the machine shop about what it would cost to get the stock rods resized and the crank turned. That would most likely be cheaper, but I think the 383 would be more fun. As for what rotating assembly, I think something like the one below would suit you well.

Rotating assembly:
http://www.jegs.com/i/Eagle/356/B13...52B040/10002/-1

As for the cam, I think the XE262H would be great. It would provide a ton of low end power but still make some decient power up high.

For the heads, I would go with the Vortec heads out of Jegs. If I am not mistaken, the Dart SS heads are more or less a stock type casting. If that is the case, the Vortecs will significantly out perform them. Jegs sells a set of Vortec heads that can handle .475 lift for $578 a set which will work perfectly with the XE262H. The vortec heads have 64cc chambers which would put you at ~9.7:1 with the rotating assembly above. That would be about perfect as long as you run premium.

Jegs Vortec heads:
http://www.jegs.com/p/GM-Performanc...749896/10002/-1

The only down side to the Vortecs is that you will have to buy a new intake. I would recommend a performer RPM air gap for vortec heads. The vortec heads also require self aligning rocker arms and center bolt valve covers.

I cant say for sure what you would be looking at for HP, but I had a 355 with vortec heads set up for .525 lift, the XE268H cam, and a performer intake and that motor ran awsome. I never had it to the track, but I would estimate it at 375 hp based on other combos and low 13's in the quarter.

Here is another engine to compare to. This is a 355, but it has the same heads, cam, and intake I am suggesting except that it has 1.6 rockers. You would not be able to run the 1.6 rockers with the vortec heads since they are limited to .475 lift.

The numbers in this test are surprisingly high to me, so you may want to take them with a little bit of a grain of salt, but I think they do go quite a way in showing the potential of the Vortec heads.

http://popularhotrodding.automotive...tec/index1.html

Adam

I haven't bought the heads yet. What is out there in the Dart SS price range that will be a better choice for my purpose. I have read that I need to stay under 180cc flow to maximize the low end torque and throttle response. I looked up the cam you suggested. It looks like a good choice. Will cast pistons give me the durability and still manage the power or should I go with forged? I don't intend on using NOS or supercharger. Thanks again for the advise. Rich

RHS Pro Torker with 170cc runners is a great street head. You could gain some power by going with a larger head, but for a good bolt on head with great low and midrange this is hard to beat. A bare set will run you about $500 and figure on another 4-5 hundered to finish them out.

The Vortecs are a 170cc head. One reason that they perform as well as they do is the location of the intake port which is raised slightly over a normal chevy head. This is also why they require a special intake manifold.

Adam

the eagle rot assembly is what i have in my short block now, nice kit, comes with KB hyper pistons, if you build a 383 vortec heads are nice but dont flow as much as everyone thinks out the box only about 225cfm@.500 and that is if you are using the L31 vortec the others don't even flow this well, but the L31's do have a good accelorant flow up to .500, the RHS pro-torqer's are a good mild 383 head, so are the RHS pro-act 180's they both flow over 250cfm @ .500 with great low end, and if you ever chose to up the cam the 180's flow well to .600" lift

in a 355 the mega264 or the XE262 would be a great street cam, but for the 383, with the extra cubes, i would look for a cam in the 270's (advertised) and the 230's @ 050, with around .480-.490 lift, but this in a 383 is making over 400hp and well over 400tq, 13's easy!!, reliable? yes as long as you have it tuned right, (that is any motor)

As for other heads out there, I can only speak for my experience with the vortecs. I had a 355 with the vortecs and an xe268h cam that was an amazing motor. I have driven cars with more radical engines with heads that were supposed to flow a bunch more, but in my opinion, my vortec motor would have kept up with those cars. All I know is that the Vortecs really impressed me.

Here is a good site to compare a bunch of different cylinder heads.

http://www.ryanscarpage.50megs.com/combos1.html

Adam

yea it sucks i cant get onto this site from my work computer (dont tell anyone) ive heard they have a bunch of engine combo's on there with dyno run's

the Pro Torkers are basically a redone cleaned up version of the Vortecs. YOu could actually use Vortecs to create a head better than a box stock Pro Torker, but that involves porting and machining which escalates the cost quickly and unless you have a shop and a set of Vortecs already in your hand there's no reason not to just go with the Pro Torker 170's. And 270's may be suitable for soe but you begin loosing streetability, I'll admit that the 264Mega is a small cam for a 383 but it will give GREAT low and mid range which I think is what he's after. No sense in chasing a hp figure at 6000 RPM when the engine will never turn over 5000 RPM.

Thank you all for your advise and experience. This is a great forum!

nice car!

pics ?

i had a 74 ventura for a while, the only pic i have currently:


this one was crappy 3.07 ratio(250ci six and th350) so i parted and junked it after driving it a bit.,

what are you going to do about the rear axle and ratio ?

just curious.

good luck!

I have had a couple of Venturas, both 1972.

Old one





New one

NICE! i love the flat black and the fab valve covers

a 3.07 ratio wouldn't be a problem, but the rest of the drivetrain may be, or the car for that matter. Make sure everything is strong enough to handle al of the torque you'll be putting to the ground. If you run sticky tires this becomes even more important. You'll probably be just a little under 500 ftlbs which can be a lot of twist to handle.