i'm putting a sbc in my 51 plymouth. i originaly planned on a 305 that I had. i read the 305 tech archive and sounded like a good idea. so i ordered a performer intake and an edelbrock 600 carb. a week ago a buddie of mine gave me a real low milage vortech 350 if you look the #'s up it says it's a 4 bolt main 350 the same block they use for the zz4. the 305 i have runs good but i have no idea how many miles. I can't afford a rebuild on either and don't want and can't use the vortech heads. my question is i have the 305 heads and i have a set of power pack heads. which should I use? thanks in advance.
i'd go with the 305 heads, the power pack heads are too outdated. just keep the engine together and run it how it is. just my opinion.
I'm a big fan of the Vortec motor. I have a fresh one waiting in the wings right now. You said it's low miles. is it a good motor? If so, return the performer for one that fits the vortec and run it. You will be looking at 270 hp vs, 150 hp with the 305. Well worth the trouble.
oh, please use the vortech heads...way better than anything gm put on stock.. your performer will work if you take a diegrinder to the holes.. i have some spacers that come with some " universal" intakes i can send you ...better yet, sell your intake to a buddy and buy the vortech performer.. for sure , you will be better off with the vortech heads...
I bought the intake on ebay so i either have to sell and buy another or fiquere something else out. and i have finned valve covers for normal heads. if the spacers dave lewis has will work that would be awesome. i could then buy the adapters for the valve covers.
That intake will not fit Vortec heads at all it is about 1/2" too narrow......Also on Vortec ALL the intake bolts are stright up verticall not angled at all.....
I have used non vortec intake on vortec heads with the holes routed out in the past..before edelbrock etc. came out with the proper one...company called power plus makes victor jr/ performer copies (china casting, i'm sure) that come with std bolt pattern and oval holes.. that is why i have the spacers left over from the last circle track motor i built.. i willbe glad to mail them to you..pm me dave
Use the 305 engine with the Performer intake. The 350 with Vortec heads is okay, but all you'll notice if you run it is that is uses more fuel. For your application, the 305 will do the job nicely. I'd run it and sell the 350 engine if I were you...but that's just me!!
There's 2 versions of vortech head. One has a big bump in a runner and doesn't flow well, the other is about the best performance value you'll find in a stock head. Do some casting # research, and if it's you've got the weak version, don't even consider the conversion expense. If you go vortech, use only the GM intake ga$kets. Other brands leak. Voice of experience here. 305 heads probably won't boost the compression since most vortechs are already medium chamber. They will also kill it's ability to breathe with their tiny runners. The old power pack heads are 283 I assume? Also tiny heads. Consider selling any 2 sets and buying a set of used aftermarket castings. I've recently picked up used iron eagle 180s for $375 and alum performer rpms for $500, assembled and useable. IMO, at those prices gen 1 sbc factory castings are hardly worth considering. Good luck either way!
Sounds OK Dave but I don't think Ill try that spacer deal on an intake...I have enough trouble using the normal parts!
I'd really like to see some photos of those spacers. I could use a set. I know some of the GM perfomance heads have a pattern for late and new manifolds. The manifolds shouldn't be all that hard to adapt.
A common mistake is that all center bolt valve cover heads are Vortec. All Vortec small blocks have center bolt covers but also have raised intake ports, and intakes with 8 attaching bolts,4 per side. As opposed to earlier engines with 12 intake bolts, 6 on each side. They are not interchangeable. Vortec engines also have roller lifters. 305 heads will work on a 350, but they bump the compression quite a bit. the smaller valves are shrouded by the smaller chambers. Performance is way down. If you have a true Vortec, you will be very happy. invest in the correct intake.
Decide what you really want...if its power Vortec...if its bolt and go...305 if you go vortec get the correct manifold like flatbush said.
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