350 top end kits

[bigtruckboi2000]

Well once again I'm back for more info. This time I'm asking about top end kits. The one that has my interest is the Chevrolet Performance 12558060K1 Vortec Top End Kit from Jegs. Would it be worth the investment over the Torker II manifold and 305 H.O heads? I also plan on putting a retrofit roller cam set up in also.

[chevy_mike]

IMHO, unless you are going aluminum, I feel the Vortec heads are the best bang for the buck of heads out there. They really flow some good numbers for a stock, steel head. A little bit of work and they can out perform many aftermarket heads.

Biggest thing is to not get crazy with the valve lift in stock form. Screw in studs help to allow larger lift but there are a few other tricks to do as well.

Don't forget, in stock form, you need self aligning rocker arms.

[bigtruckboi2000]

Chevy mike I'm not trying to do anything crazy with it just keep it a daily driver. So that top end kit would be a good improvement is what im getting.

[chevy_mike]

Remember, everything is a system. If you change one thing, everything else needs to compliment the change. Without knowing your cam profile and compression ratio, it's hard to know exactly what will happen. If your CR is too low with replacement heads, then even HiPo head won't do anything to help. If your cam doesn't have the lift or the profile is too aggressive, the wrong heads can make less power.

With all things being equal, a stock, base 350 (this means stock everything) will see a typical 40-60 HP gain. Since you have 305 heads, your CR could be higher than the Vortec heads and you could end up losing power by lowering the CR. That said, most 305 head are not known to be good flowing heads so even if your CR dropped a little (like .5) you will likely end up with better, usable power.

Agian, you have to really know what the numbers are with what you have to even have an idea of what you might get. Everything is a system and all the pieces need to compliment each other.

Good luck.

[bigtruckboi2000]

Originally Posted by chevy_mike

Remember, everything is a system. If you change one thing, everything else needs to compliment the change. Without knowing your cam profile and compression ratio, it's hard to know exactly what will happen. If your CR is too low with replacement heads, then even HiPo head won't do anything to help. If your cam doesn't have the lift or the profile is too aggressive, the wrong heads can make less power.

With all things being equal, a stock, base 350 (this means stock everything) will see a typical 40-60 HP gain. Since you have 305 heads, your CR could be higher than the Vortec heads and you could end up losing power by lowering the CR. That said, most 305 head are not known to be good flowing heads so even if your CR dropped a little (like .5) you will likely end up with better, usable power.

Agian, you have to really know what the numbers are with what you have to even have an idea of what you might get. Everything is a system and all the pieces need to compliment each other.

Good luck.

Well chevy mike thats my biggest problem, I don't know what the CR is or how to get it, dont know what kind of pistons are in it or anything about the inside of the engine. So I'm kinda stuck...

[scottofksu]

Assuming your H.O. Heads are stock, they should have 58cc combustion chambers. Stock vortec heads (906 and 062s) are 63cc, so you'll probably loose a bit of compression. I think the other (previously listed) benefits of the vortec heads would more than make up for this... However, the circle track guys have been known to angle mill vortec heads to up compression. For example, angle milling the heads 45 thousandths will drop the chambers to approximately 57cc.

[bigtruckboi2000]

Well i've mos def made up my mind about the Vortec heads (060) just tyring to narrow down the vortec manifold that would suit me best.

[bigtruckboi2000]

Thinking imma go with the performer vorten manifold and call it a day? I'm thinking that once I get the current top end off I can see what kind of insides it has and get what i need to figure out what kind of cam i want for later on down the road. Can anybody tell me what info i need to get once i get the manifold and heads off?

[NCD1966]

also an easy fix for vortec heads getting more lift is using beehive springs for LS1s, they have a max of .650 lift but if you use them on vortecs they max out at .550
I did this with my current motor in my 66

here a article about it
http://www.carcraft.com/techarticles...ade/index.html

they list two Part numbers, I'll have to look up the ones i use

btw my heads have no machining done to them

[NCD1966]

here is the springs

http://www.summitracing.com/parts/CCA-26915-16/

you will have to use these Valve Locks
http://www.summitracing.com/parts/CCA-648-16

[bigtruckboi2000]

I'm not a versed gearhead NCD1966 but after reading the article it seems like a simple way to improve the performance of the heads. I think imma do that too.

[NCD1966]

any questions just ask me I've been down this road a few times.

I redone the 355 in my truck twice and my dad a has a 383 with ported vortecs, (2.02/ 1.60 valves)

[bigtruckboi2000]

Originally Posted by NCD1966

any questions just ask me I've been down this road a few times.

I redone the 355 in my truck twice and my dad a has a 383 with ported vortecs, (2.02/ 1.60 valves)

Thanks NCD 1966. My other issue is knowing what information i need to compile and get once i get the manifold and heads off so that i can figure out what type of cam suits me.
I keep hearing i need to know what my compression is. How do i figure that out?

[ChuckW]

My only input would recommend that you stay away from the Torquer II manifold. The original Torquer with the straight runners worked great on SB Ford motors. The T II never really lived up to expectations. I'd recommend you stick with an Edelbrock Preformer duel plane riser. Much better Chevy street performance..... Just my 2bits.... Good luck.... No matter what you end up with it should run great!!

[bigtruckboi2000]

Originally Posted by ChuckW

My only input would recommend that you stay away from the Torquer II manifold. The original Torquer with the straight runners worked great on SB Ford motors. The T II never really lived up to expectations. I'd recommend you stick with an Edelbrock Preformer duel plane riser. Much better Chevy street performance..... Just my 2bits.... Good luck.... No matter what you end up with it should run great!!

unfortunately the Torquer II is what I have on there now Chuck!! And I haven't been able to find anything to convince me to keep it. I was leaning towards the performer dual plane already so you let me know I'm looking in the right direction. Thanks for the input Chuck.

[paulspickupparts]

Scroggin Dickey has sold a lot of the vortecs over the years and sell a Z28 spring good up to 520 lift. Pretty reasonable. If I am not mistaken you do not have to machine. Good heads . If you want to go over 520 lift comp springs are better but will have to machine. Chevy High Performance has a great article or articles on the vortecs and updates.

Edelbrock Performer RPM for vortecs is a great intake. The air gap version is good too but if you live in a cool winter climate may not heat up as good.

400 horse is pretty easy even with a flat tappet cam.

Once you have your heads off and can see your pistons you can get a rough idea of compression. Also easy to measure how far down from the deck will also affect compression ratio. If it is down a ways you can use a shim gasket (felpro 1094) to raise it about a 1/2 point.

[NCD1966]

i would run a edelbrock performer series intakes. all of them are great, I've ran them all on different combos.

im currently running the super victor vortec (tall single plane), I read on other forums and it suppose to make more torque and hp than the performers. and my little engine has alot of low end power
its a great motor, starts like a fuel injected motor even on a cold week long start.
it wont die and Im running a proform race 750 carb with no choke!

[cdowns]

i see alot of guys waste money on "top end kits" by putting them on old worn and tired blocks that are not worth putting anything into

i have no real opinion until i know what a topend is goin on

[bigtruckboi2000]

I'm not sure where the engine came from cdowns but I got the truck from my uncle who never drove it. It sat under a carport for at least 10 years after he bought. The eight years I've had it I have put about 6,000 mles on it highway and city miles with no problems out of it. So I'm thinking the block is in good shape.

[bama63]

i have used these on several engines https://www.patriot-performance.com/...&cat=76&page=1 and you dont have to buy new valve covers or intakes as these heads accept both styles here https://www.patriot-performance.com/...&cat=76&page=1 they are assembled and ready to bolt on

[cableguy0]

305 heads in any form are the absolute worst thing you can do to any 350. 305 heads will improve compression ratio but the complete lack of air flow and small valve negate any performance gained by the higher compression. The torker manifold is way outdated as well. A modern performer rpm intake will be leaps and bounds ahead in both performance and driveability. Vortecs dont flow much air past .480 lift. Cutting them up to fit bigger springs and clearancing for more lift really doesnt do much good. If your planning a cam over .500 lift look for a different set of heads. Most times porting a set of vortecs does more harm then good. They flow good because of port velocity not port size. If you open the ports up and screw up the runner shape your more likely to actually lose flow. It really comes down to how much money you have to spend. Just remember its usually cheaper to spend more in the first place. I agree with cdowns putting fresh heads on an old bottom end rarely works out well. You usually find out that the rings arent quite sealing as good as they should be.

[bigtruckboi2000]

Originally Posted by cdowns

i see alot of guys waste money on "top end kits" by putting them on old worn and tired blocks that are not worth putting anything into

i have no real opinion until i know what a topend is goin on

So is there anything in particular that I should look for when I pull the old manifold and heads off cdowns?

[cdowns]

things i would b checking would b the condition of the crank bearings and the condition of the timing chain and gears// lots of wear on either of these means lots of hard use and i would shy away from spending alot money on it


i'd also try a compression test b4 disassembling tho not foolproof it's a rough indication of ring sealing// lookin at cylinder walls too helps if u can see some cross hatching from honing that is a real bonus in the condition factor

[bigtruckboi2000]

Originally Posted by cdowns

things i would b checking would b the condition of the crank bearings and the condition of the timing chain and gears// lots of wear on either of these means lots of hard use and i would shy away from spending alot money on it


i'd also try a compression test b4 disassembling tho not foolproof it's a rough indication of ring sealing// lookin at cylinder walls too helps if u can see some cross hatching from honing that is a real bonus in the condition factor

Thanks cdowns. I'll do all of that, or have my mech do all of that and see what turns up. Hopefully everything will checkout good and I can keep it moving!!

[chevy_mike]

OR.... you can just leave what you have on (I assume it is running) and just drive the heck out of it! All that cash for upgrades buys a lot of gas....