Hi!

I plan on replacing the sb in my 69 4speed with a BB Crate motor. Years ago with my first C3 I gathered all the parts, found a rebuildable core and built the BB myself. I’ve done the math for this build and it really doesn’t make sense to go through that hassle again especially trying to find a competent machine shop that knows old motors. That was surprisingly tough the first go around.
I have a few questions for you BB guys that went crate.

-where did you purchase?

-what did you pay for a 502?

- did you replace the cam before install? I’ve heard that most suppliers under cam the crate motors?

-if you changed the cam, what did you go with?
-who went EFI?

-for those that went EFI what manufacturer and why?

- any draw backs to EFI on a BB?

-crate motor blocks do not have mounting points for a Z bar so a hydraulic clutch is required correct?

What else should I be aware of with a crate motor compared to building my own?

Thanks
Wade

 

I can answer a couple of your questions. i purchased my 496 from Mark Jones (Vortec Pro) and was worth every penny. it was 3 years ago so i'm sure the price has changed. check his web page for current pricing.
And you will not have to worry about the engine being under cammed!

Pat

 

I second this......I have been to Mark's shop (about one month ago) and it is surgical......he has an extensive background in Super Stock and Top Stock which use all factory castings and know how to get the most out of factory parts.
He did a set of Large Oval Port heads for me and they are perfect.......
If you want a hand machined and assembled Big Block for as much as a crate engine......talk to him. You will get no better work.......he is now my machinist (He lives 80 miles north of me in Georgetown).
Thing I like about Mark is he lets his work do the talking......

Jebby

 

I just went through this, my ‘69 has always been a SB, had some issues inside and instead of fixing it I deceived to do a new engine. After a long time of looking I decided to go crate engine, for the cost of parts and machine work, (if you can find a good machine shop) I was very close to the cost of a crate engine. I decided to go with a Skip White engine, did a ton of research, also considered a handful of other big name builders but SW was the best fit. I went with their 582 revised prostreet engine. It was a handful making fit! Since I had so much cubes I needed big header tubes, I went 2 1/8” headers but I run side pipes so very close. Actually could use 2 1/2”but didn’t want to go through custom headers. It also has tall valve covers to clear the rocker girdles. This caused issues with clearance in the fire wall. I’m battling some issues with the water pump right now but that’s not their issue. So far I am very happy with the engine, it made over 800hp on pump, seems to run very good so far.

the price point for this setup was extremely hard to beat and I’m happy. Unless you want some of the same problems I fought, I’d suggest staying with smaller headers, short valve covers and a short intake. My L-88 hood also will not fit.

good luck

 

 

The most important thing to watch for when purchasing any crate motor is what parts are installed and where they are assembled.
Most crate motor manufacturers use cheaper lower quality parts to keep the price down and many are assembled by an assembly line process most not located in the USA.
You would be surprised when you do your research and read, remanufactured block, remanufactured crank, remanufactured rods, remanufactured heads, etc…
As stated above, find a good well respected engine builder like Mark Jones who will build you an engine with the best quality parts affordable and who has the best reputation.

 

Just as a reference, I just got the new Summit catalog the other day, and I noticed the Chevrolet Performance 502 crate jumped like 30% in price from last year’s catalog, while the BluePrint crates seemed to stay the same or increased slightly. So definitely shop around.
Good luck, and let us know how your swap goes!

 

The Goodwrench 350 went from $1500 to $2200 in one day two years ago and never went back down.......no explanation. GM does not care....you want it, you want it.....if not, then pound salt.....

Jebby

 

You are NOT going to get a better big block than VortecPro. Mark Jones is a master......the only problem is he is a one man shop for the most part, and has alot of people wanting his engines. It will take awhile to get one. But...its worth the wait. I highly recommend him.

 

Pace Performance carries GM BB engines with a 2 year /50K mile warranty in many different configurations .
www.paceperformance.com
I bought their ZZ4 SBC engine several years ago and am truly happy with it.
They have excellent customer service as well, they helped me make sure it fit into my 80 model C3.

 

Thanks guys! Mark’s 650 HP 496 looks like it is exactly what I need. The 700 HP is nice but not sure it’s worth the additional $3k. Thoughts?

 

You only live once and you can't take it with you. I wish I had Mak build mine.

 

Just an fyi, if you go with a Gen V block or similar without the Z bar clutch cross shaft hole, there are brackets available that bolt to the bellhousing and provide a mounting point so you don’t have to go with a hydraulic clutch.

 

A big chunk of that price increase is probably the AFR heads. with mine i told Mark i wanted Brodix Race Rite heads so it was a little extra in price. also he recommended a cam with slightly more lift than the cam he normally puts in the engines - said it would take advantage of the flow numbers of the heads at the higher lifts. My engine dyno'd at 672hp with the Race Rites and cam. AFR's are good heads but they might give you clearance problems with your headers due to the raised exhaust ports.

Pat

 

I did a 496 about 10 years ago. Full 4340 forged internals (internal balance) short block from a guy who did offshore boat engines (name escapes me right now). He also specced and installed cam. AirWolf cylinder heads from Dr J. About 6k in long block.

I ran carbs for two years (stock tripower and then mechanical secondary tripower). Went EFI with FAST XFI ECU back in 2014. Worth it for the driveability and ease of start. Cam is 240/245@.050" lift. Idles at 850 rpm. Pulls to 6000+.

If you get the right block, you will have the Z-Bar mounting hole. Mine is a MkIV BBC so I have two piece seal, mechanica fuel pump provisions and the clutch hole. I beleive the Gen 6 has the hole (if not, there is a bracket you can get). The Gen 6 would also give you a one piece rear main seal (mine leaks). Mechanical fuel pump provision is not needed if going EFI.

Older pic, but you get the idea.

 

I love the idea of a 650 Hp 496, but I am biased.
There are down sides to building a big Hp engine for our Corvettes and trust me I know each and every one.
The rear differential is designed to take about 450 Hp tops.
If you plan to use all that Hp expect to spend the big dollars to upgrade the rear differential using all the best internals with 1480 outer axles, half shafts and u joints.
Figure about $7k to $8k minimum.
Total rear suspension upgrade to keep the tires connected to the pavement.
Drive shaft upgrade with solid spicer u joints.
Half shaft and drive shaft safety loops.
Transmission tunnel modification to make room for the larger u joints.
Transmission upgrades, bell housing and clutch upgrades.
Cooling system upgrades.
Custom built or tall L88 hood.
And if you want it to ride and steer well new front suspension.
And so much more.
I’m sure I missed some stuff.
If I did mine over again I would keep the Hp and Tq to about 500 and no more.

 

I would lean toward a good builder using a Dart block and do a 540 at least with some real heads. No reason not too once you're buying a rotating assy anyway. GM has some ridiculous prices on stuff with lack luster power for the $$$. For the $$$ you can get a lot more power, much better parts and reliability.


JIM

 

I had a local speed shop owner help me build my first Big Block Chevy engine. I bought the parts I needed through him and we assembled it while together allowing me to learn and understand better. Using a basic GM four bolt block and GM cast iron heads we were able to coax over 560 hp. The head were professionally flowed and every piece of the rotating assembly is Forged. I ran 12.25-1 Compression ratio and it works great with the corresponding L88 parts. I have about $8k in the engine itself and I learned a lot about Big Blocks. My engine builder used to build Can AM engines for Porsche, GM and Ford in the 1960's. He had a lot of tricks and kept the engine build area immaculate. This engine is way more than most Corvettes can use as traction becomes a big issue, once you get traction then you start buying rear end, suspension and other expensive parts. How many people really need to be able to do a 10 second quarter mile?
It was fun at first but in the long run it is highly impractical. My Daughter wants to inherit the Corvette and I am toying with dropping the compression before handing it over to her. The L88 engines were really too much for daily driving, if you are able to let it run it is great fun because it pulls hard past 6000 rpm

Yo Amelio, You mention that the L88 Hood doesn't fit your car, Have you tried the low base plate made for the L88? I have my 427 sitting in the car with a EFI system on top of the Edelbrock Air Gap RPM Intake manifold and it still closes. It is tight but it does work. I have a Factory 1968 L88 Hood and all the necessary parts to use it. With a functional air box it really does get cooler air into the combustion chamber and this allows you to drive on the roads with 12.25-1 compression. I have a water/methanol injection system on the engine for when it is very hot outdoors or I get stuck in traffic. It is supposed to add 20-25% more power when being used, I have not measured it with the injection system dumping the alcohol into the mixture.

My 427 L88 Replica engine is now a Fuel Injected BB and I have been very happy with the quality components and the way it runs. I chose to use a Holley Stealth Sniper which keeps the carburetor in the same orientation as the carbureted engines. Many people don't look closely and notice that it is in fact a Fuel Injected engine, it truly appears like a standard engine with a carburetor. I bought my EFI system from a company who had all the parts in stock and came in several hundred dollars BELOW my budget for a EFI system. I was also looking for the very best in Post Sale support as I didn't want to buy an expensive paper weight. Efisystempro.com gave me 2 years of tech support post sale as well as a great price and support. They have a ton of information on their website and are very helpful if I had any questions. IF you want to buy a good EFI system and get GREAT Support I highly recommend the folks at efisystempro.com.

 

Having an original 69 SB car you will have to upgrade a lot of stuff to go BB.
Two big issues you need to consider:

• What kind of hood do you want? Even a LT1/454 hood needs a flat BB intake to stay under. The L88 hood lets you go with a mild 2 to 2-1/2" high L72/L88 intake. Nothing more. Many aftermarket HP BBC intakes are very tall these days, like 4 or 5 inches. Then you will neeed a very tall hood scoop. These intakes do not fit in a C3 well. The hood is much lower than a C2 or Camaro or Chevelle. Max under the hood power with the flat "569" intake is around 500ish. to maybe 560.
• Once past 450-500 HP, if you have wide tires and traction, you will go above the limit of the IRS & the entire drivetrain and had better reconsider upgrading virtually every component past the clutch. That will cost as much as the engine will.

Those are the two reasons Rescue Rogers and I both stuck to the low 500s for power. It is so easy to build a lot more power these days, but is it worth cutting up the rest of the car? Or worrying about breaking it all the time? My 500ish HP LS6 454 is very driveable And should run low 12s. I could have easily made mine 560HP , for the same money, but decided "why"?

 

When I had the 489 engine built for my '68 L36 4 speed/3.08 here in the UK I worked on the basis that if the Vette chassis was good enough for GM's L88 engine and its supposed 550 or so hp then it would be good enough for my project. I wanted to retain stock driveline components so the car could be returned to stock if required. The L88 style hood was certainly needed with the Performer Air Gap inlet and yes, underfloor 2 1/8" Super Comp headers were also required (along with their very limited ground clearance). A DeWitt OEM style radiator was also needed for cooling. With a 234/240 flat tappet hydraulic cam and Brodix Race Rite Oval port heads it ran 571hp/606ft/lbs tq at 5900/3800 on the dyno. I installed a Centreforce Dual Friction clutch and steel flywheel, also 285/40/18's on the rearend for grip........and the driveline has all held togther (so far). With its 950 dp carb cruise fuel economy was surprsingly fractionally improved over the old 427 engine.