Hey all long time reader brand new member. First of all I would like to say thank you for all of the useful material that you offer here at this site it has been a huge help to me so far in starting into the world of Corvettes. I just bought back in February a totally stock 1977 Corvette with 65000 miles. I am always wanted one as a kid growing up and finally had the opportunity to get one. I have ordered a lot of parts to start doing upgrades I am curious if there is anything that I need to look out for when I start swapping things out and and also what kind of power and torque do you feel like I will be getting?
First first of all I bought a set of 062 Vortec heads
*Comp cam Xtreme Energy Cam and lifter kit with the following specs
Duration at 050 lift. 218int./270exh.
Advertiaed duration- 262int/270exh.
Intake valve lift w/ factory ratio rocker arms- .462int/.469exh.
lobe separation 110
Grind number- CS XE262H-10
oustide diameter of outer springs 1.254in.
*I also have already bought summit vortec dual plane intake manifold
*Edelbrock 1405 600 cfm carb
summit racing G9003 full legnth headers
Finally Patriot exhaust 60 in side pipes.
One big question is can I use the push rods from my L48 heads or do I need to order some aftermarket ones... I feel like based on what I've read I should be fine but would appreciate confirmation.
about where do you think I will be horsepower, torque and compression ratio wise?
Finally, do I need any shimmed head gaskets or anything like that or will the standard let's say felpro work fine?

 

First: Welcome to the Corvette Forum!!

Second: When you have a car that is really original then I might suggest that getting another engine block and saving the original in large Plastic bag with all the holes plugged up and grease on the cylinder walls
I have a 1968 L71 convertible with the four speed. When I got ready to redo the engine I searched and found a cheap replacement ($200 for the long block) It was a cinch to install and ran great while it. The engine I bought turned out to be 1970 LT1 engine with double hump heads on it. I was able to drive the car and enjoy it while the 427 was being built, it took over 9 months before we finished the 427 so having another spare engine was a real blessing.

I did my rebuild in a different way than most. I had a friend who owned a local Speed Shop and he and I worked out a great plan. After disassembling the engine my friend and I built it together as I have built dozens of air cooled engines but this was my first big block I ever owned and I did not want to hurt it. The agreement was that I would buy all the parts from him and he and I would assemble it after hours. My friend had tons of experience with american engines and was also a Porsche expert.
This guy spent hours on each piston and ring set getting everything matched and made for making power. By the time we were done my buddy had a line of people waiting to do the very same thing. He could have sold my engine several times just at his company Christmas party. The engine was finished and on display! This deal worked out great for me and turned out to be a win-win for the both of us involved.

Having a spare engine made me slow down and take my time to do it properly and not in a hurry. Building an engine can be done fast assuming you have done it before. I also benefited because the smaller 350 really helped me appreciate the 427 when I finally had it installed. By the way I had a Corvette Restoration shop install the 427 for me, they redid the engine compartment and painted everything and when they finished I was ready for the car shows.
All in all it turned out great in my situation.

I wish you the very best in your endeavor!

 

That sounds like a really fun toy you have there! I plan on slow building a more powerful engine. I don't have the space to do it now though or time. Just had a baby this past month so that will be the plan when things settle into a new normal lol. With that being said I need to pull the motor out and replace some stuff anyways so I figured I'd might as well go on and upgrade what I have. I'm not too concerned with keeping it stock as I will stockpile all the original parts if ever desired to put it back how it was I will have all the pieces in a box(or 20 lol). I truly appreciate the response though. On another note, I have taken down and put together several engines changing head gaskets pistons complete rebuilds etc. Also have a certified mechanic as one of my best friends that will be assisting me to help move things along. I'm on a bit of a time crunch however as I need to have it done by mid Septemberfor an event and will be pulling the motor this week while my interior is being redone and new tires getting put on . That's why I was hoping to expedite anything I can by leaning on the wisdom of the forum to help me troubleshoot any possible issues before they ok i.e. with the pushrods question. I am still very curious to get some guesses on where you all think I will end up with this particular setup in respect to hp and torque.

 

Build another motor? Not sure thats feasible for him
OP youll need to measure your pushrods when your heads are on, Summit sells the checker spring and tool. WIll they fit? Possibly
I wouldnt go to thin on a headgasket, stock replacement ought to do. Few guys here have done this maybe they can give you an exact PN for both gasket and pushrod length.
Manley makes some good stuff thats reasonable.
If it were me upgrade to a better pushrod they arent much, get the 1 piece. Nothings worse than standing on it then bending some pushrods, no fun.
Fun combo you will have there, youll like it.

 

Looks like a good list of parts. Will the 062 Vortec heads accommodate the lift on the cam? I seem to recall hearing 0.420-0.450 lift being the upper limit for a stock head. You may want to check before you get too deep into the build so you can correct it now if that is the case.

 

x2. Seen figures quoted from GM as low as .435 who knows, best to double check. Fortunately its cheap to have the guides turned down some if need be.

 

BigBlock77 and cuisinartvette are right about the heads - check the lift, and expect to machine them for more (it is not expensive). I did a very similar build using vortecs and a roller version of that cam - it worked pretty well, and I ended up with a nice little 355 with good torque on the street. I never had it dyno'ed, soI can't guess at HP/TQ numbers, but it ran really well. Then I got hungry for more....

 

Thanks for the replies. Keep em coming! The more input the better can never have too much information right?!? I have access to a local speed shop that I know the owner of I will reach out to him and see if clearance will be an issue. How much would you expect me to need to "trim" to accommodate the cam with the lift? Can't wait to get it all together and see all the hours I've put into it come to life. I'm presently in the garage painting the headers lol. Going red on the heads headers and intake manifold. Haven't gotten to painting the heads yet but will wait till all prep that is needed completed is done before I do. Plan on doing black block with red top half and top add the finishing touches chrome filter valve covers and timing chain cover. What do you all think? Absolutely want red in it because it's my wife's favorite color. Lol

 

Here's two articles as a primer for the head modifications. I've read several articles through the years in Car Craft for this, but haven't had to do it myself as I went with a big block for my build. If you don't feel comfortable modifying them yourself, this would be an inexpensive modification at a machine shop. Your buddy at the speed shop should be able to point you in the right direction there. It would have been MUCH cheaper to go with Vortecs, but at the time I started with the engine, the Vortecs weren't even hitting the junkyards yet. You should be able to make some good, driveable power with this combo without too much $$$ tied up in it. Good luck. :-)

http://www.superchevy.com/how-to/148...ds-valve-lift/

https://www.powerperformancenews.com...benchtop-mods/

 

It is Bubbaesque, but i cut .050 off my intake guides with a right angle grinder. And left exhaust seals off completely. I believe you need rocker arms, or rocker stud-guide plate mods. Is your compression good? If rings are getting tired, you will finish them off with more compression and more right foot. OTOH, it won't happen overnight.

 

I used original L48 pushrods with that same cam in my engine, with 062 Vortec heads. I had the valve guide bosses cut down so there would be no question about the lift limit. I used Felpro, blue, stock type head gaskets. You will need self aligning rocker arms. Make sure you use high zinc oil.

 

Hey guys thank you so much for all the feedback. Bkbroiler do you happen to remember how much they were cut down and how does yours run since the upgrade? Does the cam have a nice sound to it?

 

 

I don't remember how much they were cut but it was a lot because I later changed to a hydraulic roller cam with .550 lift on the exhaust with no problems.
My engine is a 383, with 9.7:1 compression ratio so even when I had the XE262 cam in it, it's not a direct comparison. I did run 12.30s with that cam and the Vortec heads. But by that point I had some porting work done, the heads were milled, spring pockets enlarged, screw in studs installed and pushrod holes enlarged to use with 1.6 rockers.
As for the sound, not very radical at all at idle, but the extra cubes account for some of that. Overall though, I think that is a great cam for your setup.

 

Hello again Dcott,

I apologize for offering a "slow" way when you are in fact on a schedule. Having the friends you have, you should be in good hands. I have rebuilt diesel engines in the deserts of the middle east but had never done a water cooled V8 like my 427. I was in a search for maximum power when I built my engine but could not afford some of things I wanted to do. Roller cams were available but expensive. Aluminum heads were out of site price-wise. For your engine, the parts available today are incredible, the power is there for the asking. You have a lot of choices to make and how they interact is always fun. Since I ran high compression my buddy and I put clay on top of each piston and then rotated the engine a couple revolutions, this was a pain in the butt but gave me some comfort knowing I had plenty of room between pistons and valves in my closed chamber heads.

What did you paint your headers with? I have never had any luck with painting headers, the high temperatures coming out of the head burn the paint off right away. If you have any problems with burn off you could get them coated for a couple hundred bucks in a variety of colors during the winter months. Currently I have a set of Hedman headers that came with the silver/chrome coating on them. The aftermarket coatings can reduce your engine compartment's temperature.

You did a beautiful job painting your intake manifold! When you finish the engine as you described it, it should be quite the looker as well as a performer! Car shows here he comes!

You did not mention where you live but if you are on the East Coast there is a great event that is quite worthwhile for Corvette Owners. I am talking about Corvettes @ Carlisle in Carlisle, PA. There are 50,000 fellow Corvette enthusiasts at the fairgrounds the third weekend in August. You can find so many things at Carlisle and save some serious change as well. You can check it out online. I have seen and met people that drive down from Canada and up from Key West just for this weekend of Corvettes. IF you live within a reasonable distance from PA....

Keep up the great work! You have some really good people helping you in the right direction!

 

Hey, no worries at all what you were proposing is a great idea and I plan to incorporate it into my big build over the next few years. I'm hoping to just bring the old girl to life so I can enjoy it more while building my 500hp plus (goal) engine. I plan on a 383 with a roots super charger and the biggest cam I can cram in it lol. I'll be doing a 4 bolt main for that build and pairing it with a different tranny and rear end set up. As for the paint I used vht high temp bright red for headers and the intake. The heads will be painted to match once they come back
​​back from the shop as well. I live in Maysville ky so a trip to PA isn't out of the question as I have family in the Morgantown WV area. I'd love to make it up there next year if I can manage to at all. While I do that engine I may get froggy and do the bottom end later on the current one with new pistons and what not down the road a little ways. If all goes well the block will be going to the shop(cropper race engines is the shop I am reffering to in case that means anything to anyone here lol) to get the cam and heads assembled and checked next Friday. They will be checking it with clay as well to ensure proper fitment Should have it all back together with a couple days to spare before the event (fingers crossed) lol thanks again to all of your all's input and tips it has helped me tremendously over the past few days.
i attached a better picture of the manifold in case you were interested in seeing it

 

Sounds like you have the bases covered.Should be a lot more fun to drive.
I would recurve the distributor if you haven't already.Once you get it dialed in and decide you want more power do a carb swap and see what gains you get over the edelbrock 600.Not looking to start a pissing contest or carb war.It is my opinion that carb wil run and drive fine but leave power on the table.

 

I will second the direction of BKbroiler, use high zinc oil and follow the cam break-in instructions. Don't just put in synthetic oil and think you are being kind to your engine. These engines need the high zinc protection for the kind of cam you are using.

 

Hey guys been a awhile now but I finally got the 77 put together and thought I'd share with you all...
Still ironing out a few wrinkles but it will all smooth out