hey guys I have a 350 with 305 heads

the heads that are on it are 75'-79' (60cc) 305 heads which obviously bump up the compression ratio quite a bit. the problem is the small valves 1.2/1.5
it runs pretty good; but i think the vortecs will be a good upgrade.

the vortecs are 64cc's; so at least i do not know compression ratio will be a problem; as this will obviously lower the compression ratio. I was told the camshaft was around 480 lift; I've heard vortecs can only take around 475 lift. If I remove the cam; would there be a part # on it? Also the other problem is I don't know what type of pistons that I have. Would this be a big problem; If I tear the block down is there a way to find out what the specs are on the pistons without taking them out? I'm scared of touching anything on the bottom end.

Your thoughts please guys....Thanks I'm just throwing ideas around. I think it should be a good bang for the buck upgrade; heads and intake. the car already has roller rockers.

It will be a huge improvement over the 305 heads.You should have flat top pistons or possibly the small dished.Either one will be fine with the vortecs.The .480 lift shouldn't be a problem but you will need to get a set of the upgraded heads aftermarket ones to use your roller rockers.Stock Vortecs have to have self guided rocker arms.The aftermarket and upgraded ones can handle more valve lift.One thing to consider is what you have now ( intake , valve covers etc).You are going to spend $1,000.00 upgrading to vortecs you can buy Dart Iron Eagle heads that use all of your current parts http://www.competitionproducts.com/Dart-Iron-Eagle-180-Cast-Iron-Chev-SB-Head-Assembled-Pair/productinfo/D1864AA/ . RHS Vortecs are a good buy http://www.competitionproducts.com/RHS-Cast-Iron-Chev-SB-Vortec-Head-170cc_64cc-Assembled/productinfo/RHS12407K1/ .

Get a dial indicator to measure you current valve lift. You can upgrade the springs (HIGHLY recommended) and use a retainer that'll give you a good bit more clearance without having more machine work done. I've NEVER seen a Vortec head with a stud that pulled out on it's own, I think you're fine with what you have, particularly considering the price of upgraded Vortec heads. Sell the roller rockers and use that for the springs, etc. At that lift, they're not really doing you any good anyway.
If you have time, have someone massage out the ridge in the exhaust short turn. It won't take but a few minutes and will help a lot. I use a Fordham tool (a lot like a Dremel with the flex line) and blend the cutter marks out and do the short turn work on all the Vortec heads I use. It takes about an hour per head but IMHO it's worth it. You're not porting 'em, just cleaning up Chevy's machine work.
Your compression should be fine, it's low 9's with Chevy's dish piston or right at 10:1 with true flat tops. Plan fuel accordingly.

wow those dart iron heads look like a good deal. especially since I dont need new valve covers, and intake etc...

http://www.competitionproducts.com/RHS-Cast-Iron-Chev-SB-Vortec-Head-170cc_64cc-Assembled/productinfo/RHS12407K1/

what is the chamber size in those though? 64cc? Is it worth it if I'm spending almost $900 on dart iron heads to step up to aluminum ones?

what is the chamber size in those though? 64cc? Is it worth it if I'm spending almost $900 on dart iron heads to step up to aluminum ones?

Yes they are 64cc heads.Aluminum heads are nice but its another $300 to $400 more just depends on how far you want to go or how much you want to spend.With a mild 350 I would go with the cast iron Darts.

yea you guys are right; there is no need for aluminum heads really.

the only thing i was concerned about is that I have 1.5 scorpion roller rockers; when I swap the heads how do I know what length pushrods I would need??

The stock ones should be fine.

so I could basically bolt on these dart heads assembled and use all my existing pushrods and rocker arms?? anything else I should be aware of?

I'm concerned with dropping the compression ratio too low going from 60cc to 64cc chambers?

No need to be concerned about the small drop in compression.

would I need the angled plugs? or straight plugs on the dart heads? I have hooker headers.

Straight.

so guys im definetly going to go aftermarket aluminum heads. any reccommendations? I'm thinking dart; or maybe go AFR? 180-190cc??? what do you guys think?

so guys im definetly going to go aftermarket aluminum heads. any reccommendations? I'm thinking dart; or maybe go AFR? 180-190cc??? what do you guys think?

Pull your heads off and then come back here and tell us or show us (pictures) what you have and we will be able to tell you several different opinions...err...options. That way youll know what you have when you put it back together.

I just built a 30 over 350 with afr195 heads and a 280DUR, .480 lift comp cam. I went ahead and installed 1.6 Scorpion roller rockers on the intake and 1.5 on the exhaust. 1.6 rocker increase intake lift around 30 thousands. Ive learned and been told it aids in producing torque down low. It has cheap, basic speed pro hyper pistons on 6" rods and the compression is close to 10.0:1. It has an Edelbrock EPS manifold and a 750 vac sec Holley. Its in an 84 chevy pickup with 342 rear gears and runs fantastic! Pulls hard and when the convertor locks up gets REALLY decent mileage. Points to ponder...

From vortecs to Darts and now AFR's ? Back up the money train. Here are some heads at your link that are comparable to vortecs.

http://i263.photobucket.com/albums/ii152/tjs69_photos/Heads/heads.jpg

yes the money train is backing up lol. i have a full time job now; so i want to do this enigne right. the heads I have now are 60cc; (305's). It runs pretty damn good; but I want more power.

I was thinking to get some 64cc 190 or 195 heads. I am going to the daytona turkey run next week and I might pick up a set of heads there. The only thing I'm scared about is...what about pushrods??? How do I know if I need to change pushrod length with a new set of heads? Or can I just use the same pushrods I have. I also have 1.5 scorpion roller rockers right now.

those edelbrock E-tec's looks nice; a bit cheaper than aluminum darts and vortecs.

Edelbrock E-tecs use a vortec intake and centerbolt valve covers.
Edelbrock E-streets use the old bolt patterns for your old intake and perimeter bolt valve covers.

You may want to look into buying a set of Heads bare and build them with your old parts.

Don't confuse Edelbrock E-tec's with the E-street heads that TJS69 mentions. E-tec *is* a Vortec-style head and requires a Vortec intake manifold. E-street heads allow you to use everything you currently have. I'm currently trying to piece together a budget set of Vortecs, and I now wish I would have saved a bit more money (and weight) and gone with a set of E-street's. This article has a decent discussion on the pros and cons of E-Street vs GM Vortecs:

http://www.hotrod.com/techarticles/engine/hrdp_0908_affordable_cylinder_heads/index.html

The best pricing I've seen on E-Street heads is at sdparts.com , the same place that most will recommend you shop for GM Vortecs (and others) too.

yea i definetly dont want to go with a vortec style head; as i want to use my valve covers and performer RPM intake.

i dont really want to deal with putting my old valvesprings in new heads. I just want to bolt on a new set with my old pushrods and scorpion 1.5 RR's.

Would AFR 195elim or Edelbrock E-street heads allow me to do this? i've heard horror stories of my buddies pontiac 350 where he changed the heads then bent all the pushrods because the new heads change the valvetrain geometry. I am definitely trying to avoid this!!

I would think that the Edelbrock heads will do what you want. The ports are not raised, so you shouldn't need different length push rods. If it was me, I would call Edelbrock and ask them for sure.

yea thats the other thing...is it really worth it to blow $800+ dollars on 50-60hp lol...

is that rhetorical? ha ha ha

YES! It is worth it!

yea thats the other thing...is it really worth it to blow $800+ dollars on 50-60hp lol...


YES YES it is

I got a nice set of Edelbrock Performer RPM heads used off of craigslist for cheap. Look around there are deals to be had.