Since the last thread got trashed I am starting this one. As far as engine only I am looking to take my rebuilt 355 and turn it into a streeable daily driver with 350-400hp. I'd like to not undo any of the work my machinist did in the bottom of the motor if possible and keep a pump gas compression ratio. I know I am going to have to spring for new heads most likely but would like to save the most money. My heads did get ported and polished so if my head cast number may verify my heads being worthy for the build I will post them if someone could tell me where its located. I need this list down to the very last part and links would be a huge help.


As far as what I have already:
Roller 355 Block
2piece main
Hot cam (unknown lift/dur...)
ported & polished cast heads
Edelbrock Performer manifold
Stock bottom end
I need to find out what type of pistons but my machinist said its 9:1 compression so I dont know if you can tell from that but Ill call...

 

big difference between 350hp and 400 hp.
pick one or the other.
400hp 350 can be done with vortec heads, edelbrock performer rpm airgap intake, with a 750dp holley, lt4 hotcam. with 9.6 compression. chevy high performance magazine has done this exact combo.
very unlikely your heads will get you 400hp, depends on what they are i guess.

 

To find your casting #'s: MorTec, Chevy V-8 Engine Block and Head Casting Number Locations

If you have a roller block, and the heads came with the block, you may be okay as long as the engine wasn't originally a TBI (truck, Caprice, etc.) engine.

If you go with Vortecs, get them upgraded for better springs and more lift. Stock Vortecs with stock springs aren't going to play well with a Hot Cam.

The only way piston CR means anything is if you know deck height, head gasket thickness, and head chamber volume. "9.6" means nothing, because you don't know the assumptions that went into that calculation. Most likely your pistons are 4-valve relief flat-tops.

The Performer manifold may get you to 350 HP, but it won't fit Vortec heads, and 400 HP is likely to require an RPM manifold.

 

Ah alright well i know for sure that my heads arent TBI heads the engine is late 60's... Lemme go grab my cast number...

Alright heres the numbers off my heads. 8/29 4 Under neath that 338882

 

stellar, 882 heads. You'll need a lot of luck to get to 350HP with those paperweights. I highly recommend shelling out the coin to get the vortecs with the bigger spring pockets and more lift modifications done to them. Use the 882's with their nice shiny porting as cool boat anchors.

 

Now, now, Sonix, 882's are good for more than that. They make fine doorstops, too. . .

 

Then it's not a roller block, either.

 

No its a roller block because its got a roller cam and lifters in it. It may be early 70's but I know for a fact its roller. So I guess I am opting for heads eh? Got me some nice TBI equivilent paper weights I take... Can anyone recommend a good head-spring-rocker/cam combo? Again I'm not looking to drop 1200 bux on heads...

 

If its a pre-'87 block, the only way to have roller lifters is to have a retro-fit set of lifters. They are the kind that have a little bar tieing two lifters together at the top of the lifter. Is this what you have?

Some of the 305 heads actually make really respectable performance heads. They might not get you to 400hp, but 350hp is definitly within range.

On my 350, I'm using a set of 601 casting 305 heads with screw-in rocker studs, guide plates, and 1.94/1.60 valves. They have 53-ish CC chambers in stock form, but mine are closer to 60 now, because of some work done to them. These heads flow REALLY well with proper port work done to them. Ive heard of them getting to 230cfm on the intake side! Although mine don't flow like that. The good castings to look for are 601, 416, and 081.

The 350 TPI head is also a good candidate. Its about the same as the 081 head, but with the larger 1.94" intake valve and 64cc chambers. Its casting number is 083.

 

comp XE274 cam, vortec heads, 9.5:1 compression. 400+ hp

 

Just to be absolutely clear, no, it is not in no way at all a roller block. A roller block has to be '87-later, so don't call it a roller block. As mentioned, you can put roller lifters in an '86-earlier non-roller block, but that doesn't make it a roller block.

Now, as to heads: Check out the sdpc2000.com upgrade Vortec head kit p/n SD8060RAAG. It includes Vortec heads modified for .575" lift, good springs and retainers, rockers, gaskets, RPM manifold, bolts, for about $1200 shipped.

 

what ever you do. What ever combination you come up with, as long as it does not include using 882 heads in any form, you probabily be ok.

Fully ported 305 heads with big valves will get you there. Ported TPI heads will. Ported (late)camel backs will. ported aluminum l-98/ZZ4 good.
Vortec's good. Any of the 170cc to 200cc intake port Aftermarket heads are good. cast or aluminum, your choice.

You'll need a hyd or hyd roller with 222-240@.050 or a solid flat or roller with 236 to 248@.050" use flat tops and 64cc heads.
use a 750cfm carb and a dual plane high rise. 1-5/8" headers.

 

Ah alright i see what your saying about there being a differeence between roller block and having a roller setup. I know my machinist told me it was roller so i went by that... I think I am going to try and find a junked late 90's suburban and work those heads over to save myself a few hundread bucks. How would the heads off a L98 stack against vortecs? PS: any ideas on what gas mileage will be like...?

 

90s suburban is the dreaded swirl port heads....not worth it at all. now if you're talking 96-98 L31 aka vortec heads, then that is the hot ticket.

 

Yeah late 90s

 

By the time you get them cleaned up, guides cut, new springs, retainers and seals installed, you'll have as much in them as buying new upgraded heads. And, you'd still need to get a Vortec manifold, gaskets, rockers, bolts. . .

 

What about the heads off a 350 TPI? How do they perform compared to the vortecs? I am looking to do heads within $800 dollars.

 

TPI heads can work very well for ya. If you're willing to do the work/time to fully port them. Recommend chamber deshrouding and larger 2.02-1.60" valves (Cast head). 2.00"x 1.56" (aluminum L98)
its not economicly viable to pay someone else to port these or any other stock head. Unless you're willing to do the PORTING WORK yourself you're better off buying assembled aftermarket heads or assembled upgraded vortecs.

 

I haven't read the entire post. Just replying to the initial question.

Take your engine and change the clyinder heads. That's it... easy as pie! But you're going to need good heads and they aren't cheap. GM Vortec heads are the minimum for what you need and likely the least expensive. Make sure the heads are equipped to handle the valve lift that your HOT cam provides. You will also need an intake manifold that will bolt to the Vortec heads. There's one clear choice: Edelbrock RPM. Just give Salee Chevrolet or Scoggin Dicky a call and tell them what you have.

Good luck and let us know how it turns out.

 

Thanks for the good luck. I know I am definatly not porting the heads myself so maybe I'll jump on some Vortecs... 1200 bucks isnt that steep for upgraded heads and an edelbrock manifold is it?

Anyone have an idea on mileage?

 

Compare the price of Vortec heads to something like Edelbrock, Trick Flow, Air Flow Research. The Vortec heads are a deal. Maybe not quite as potent but it will meet your criteria. You can also get some money for your old heads to help offset cost.

The mileage will be dependent on all the drivetrain factors in your car. Regardless, don't expect to get out of the teens-per-gallon. Fortunately, the Vortec heads are iron and will help improve efficiency relative to aluminum heads.

 

http://store.summitracing.com/partdetail.asp?autofilter=1∂=NAL%2D12558060&N=700+4294908216+4294840140+4294925232+4294838998+115&autoview=sku

Alright I was looking at these. Is there anything wrong with these besides the fact that they need a nice set of 1.6 roller rockers on top?

I'd be very happy with 12+ so great!

 

Don't ask us... call Salee Chevrolet and ask them. That's a safe source of info. Anybody here can say anything and you have no idea of their qualifications.

You absolutely need to tell them you have a HOT cam.

GILBERT CHEVROLET -www.sallee-chevrolet.com- (Chevrolet Dealer, GM Performance Parts, Aftermarket Performance Parts, Speed Shop)

 

Thanks for that vote of confidence. . .

r0nin89, the Summit head you linked is the standard, unmodified, truck Vortec. Not at all what you want. 1.6 rockers would make the situation worse.

I don't know about Gilbert Chevrolet, I don't see any upgraded Vortecs but I'm not all that familiar with their website. From what I've read and heard about SDPC, they would most likely tailor the package for you to accommodate your needs. 1.6 rockers instead of 1.5's, for instance, in their upgraded Vortec package.

 

Hmm well I guess I am looking at it like this, $300 manifold, $100 dollars in gaskets, $800 for decked out vortecs? Is there anything a hair cheaper than that?

 

intake is $220 for the performer RPM air-gap for vortecs through summit.

heads are $550 a pair through scoggin dickey parts center for the valve lift for the XE274 cam. fel-pro intake gaskets are cheap and head gaskets are in the $50-60 range for SBC head gaskets.

 

xpndble has got it right.
cheaper then that is porting your own heads, which, you don't want to do.

summit has a summit brand, or mr gasket brand, small block chev gasket kit, including head gaskets, for $29. I got the summit one, then the mr gasket one for my re-rebuild, they're both good.

 

Well I think I am gonna opt for the upgraded package with the manifold and gaskets for $1000.

 

550 + 220 + 80 in gaskets equals $850, are you getting a carb for $150 only for a double pumper??

 

If you are referring to the SDPC2000.com upgraded Vortec kit, that includes upgraded Vortec heads, Vortec RPM intake manifold, intake and head gaskets, head and intake bolts, and self-aligning rocker arms for a tad over $1000 plus shipping.

 

Thats what I was refering to.

 

just to chime in here. I have looked at that it as well. looks like a very good price especially taking into account that you can get 400hp out of stock vortec heads. i think with the upgraded heads, you could get about 450hp. that my goal with my 383

 

Ah sounds good... I'm still expecting 400hp seeing as how the bottem of my motor will be pretty much stock. PS: I've decided to build my own motor and not buy my dads because the heads are junk and theres no way he would split it. What should I go for for a block? I was thinking it would be good to pull a 96+ 1 piece rear main leave the bottom stock except .30over pistons. How much gas mileage would I loose going for a stroker crank?

 

gas mileage is based on your setup and how you have it tuned thier is really no way to calculate it. it would be at best a guess in the dark but if your running a carbed 383 with a vortec setup and a good exhaust and ignition tuned for 400 hp at best you would get 10-14mpg.

 

ok first off i am gonna make you mad but i think your machinist is also some sort of lab rat or somethin because no way a machinist tells someone a pre 87 block is a roller, they got totally different provisions for oiling for starters. now here is a ? no one has asked and you somehow didnt answer, where do you want to be makin the hp at. and i also saw your post about a "hot cam" is the the 460 lift cam you was speakin of? sorry dont take this personal but there is more to buildin and engine then findin some parts and stickin em in a block they all need to be matched to work together and make there power in the same rpm range.... like i said just do your homework a little bit man and you will be suprised at what you will find, o and as for good flowin heads i prefer the vortec 906's found on some of the mid 90s suburbans, they post very similar flow rates to some of the low to mid dollar dart heads. nothin personal just dont want you wastin your money to find out your 350 hp engine is really 35 hp

 

906's???? You want to find the 062's. The 906's came on towing trucks like the 2500 and such. These are more restrictive than the 062's are.