1999corvettels1

First off I don't have a C3 Corvette, but Corvette Forum has some pretty sharp people, if me not having a C3 is a issue and this gets deleted I will understand.

Ok so I have timing questions on BBC, in 2003 I bought a 1974 Chevy pickup with a 454 and TH400 from the tow company I worked for at the time, think it was $180.00 I paid, truck was a basket case missing almost all interior parts(this was in California and the 1974 truck was on a CHP impound for 30 days for a driving under the influence arrest, most junky vehicles were not retrieved after 30 days because about 1000.00 in towing and storage fees) most were sold to pick n pull for 50-85 bucks, nicer cars were sold to public from tow yard, my plan was to put the 454 and TH400 into my 1965 C10 truck, replacing 327 and TH350, and I got it done.

After getting it into the 65 I noticed it didn't seem to have much more umph than my 327, then ended up moving and job change etc, 65 on hold for years, also bought C5 Corvette during big block swap on 65.

Years later digging and looking, I found out it's not a 454 like the emissions tag said on 1974 truck I got it from, but a 1968 Chevy pickup 396 rated at 310 HP.

I wanted a 454 not a tiny 396 lol!

Anyways I've decided to try to dial in this 396 and see if it can run better, exhaust stinks bad, it has wimpy power for what you would expect, maybe it's my fault?

At the time of the swap I set the HEI at 8 degrees btdc, and nothing else, I wasn't aware of centrifugal advance and total timing etc.

Could this be the cause of the nasty exhaust?

I also bought an almost brand new Edelbrock 850 CFM Quadrajet performer RPM, I plan to rebuild it with the help of Cliff Ruffles Q Jet book, apparently it's super rich at idle for wild cams.

Since some of you have 396, 427, 454 engines, what should the base/initial timing be set at?

What about total timing?

I was planning on doing a LS or Vortec 5.3 or 6.0 swap because this engine is so wimpy, my brothers 2001 GMC Sierra extended cab 5.3 has a lot more umph than this big block.

I'm thinking now I have the timing extremely retarded and that's why it stinks and has wimpy power.

I read I should set it at 18 intial timing and 38-40 max/total timing, does this sound right?

I always ran regular gas but better get premium now, 91 octane is what the highest in my area has.

Any ideas?

Jebbysan

Do the total timing first......396 Closed chamber stuff likes 38 like you stated. Lock it down and record the initial. Write that down. Now hook up the vacuum advance and see what it pulls.....I believe most vacuum cans pull about 10-12.....now check the initial with the vacuum hooked up. Write that down. Post what you find.
What carb are you running?
A 396 should pull a LOT harder than a 327........they run pretty well all things considering.
Post what you find.

Jebby

1999corvettels1

Awesome thank you!

Next question, buy a timing tape, or just use the dial back feature of timing light and point to zero?

1999corvettels1

I had watched Wheeler Dealers episode where they do some work on a 1968 Corvette with a 327, at the end they drive the car and it sounds really good and powerful.

Got me to wondering about the 396!

TimAT

I'd take a piece of chalk and mark the "0" line on the balancer and the "0" on the tab. With a dial back light you can see exactly where things are going. That BBC should pull the socks off of the 327 without working up a sweat. Like Jebby said-- shoot for 38* at 3000 RPM with no vacuum, lock it down and hook up the vacuum- if it pings, back off a couple degrees and try again. I'll bet you end up around 12* initial with no vacuum.

Jebbysan

If it pings......get an adjustable canister.....
You need to verify 0 TDC with a piston stop. Then get a timing tape. The balancer must be cleaned with lacquer thinner before installing or it will just fly off. Dial back lights are fine.....but can be 1-2 degrees off if using an MSD or Mallory box.....I believe it is close enough for street work if it is the only option.....it gets you close do you can dial in from there.
If you get 38 degrees at 3000 rpm and the carb is tuned proper......a 396 will pull Hell off of a Cross.....

Jebby

MelWff

He will only be able to achieve that 38 at 3,000 if he gets rid of the stock distributor springs and installs an aftermarket spring kit.

1999corvettels1

Years ago I bought a "performance curve kit" that has the weights, center, and ,3 sets of springs, can't remember if it was Accel brand or what, but I read online later only use the springs, the weights and center are Chinese junk, so I put on the lightest springs.

I also made a vacuum advance stop plate, if I recall it limits the vacuum advance to 10 degrees(got the advice from someone on another forum who gave instructions), never verified it because it was summer time in Phoenix, and just like now I was supposed to get a piston stop to find TDC, then get a timing tape.

So next step is order piston stop and timing tape.

By the way it's a factory HEI from a 1977 305 Impala/Caprice, I gave my other HEI distributors and extra carburetor Edelbrock Carter AFB style to a Chevy friend because I was moving and just didn't have room in 2004.

1999corvettels1

Also I got 3 old junk points distributors which the guy said for Chevy V8, free from a mechanic shop that was cleaning out old parts and junk, stumbled onto add by mistake on Craigslist, the guy said he felt bad throwing them away.

I grabbed them just because, they seem to be hard to find, also last salvage yard I looked through didn't find one HEI distributor, these old parts seem to be hard to come by, maybe they are junk, but I grabbed them just in case, I got the 3 junk points distributors in 2017.

derekderek

A guy on here with a 396 vette felt his engine was wimpy junk and wanted bigger. He found the rug was stopping loud pedal from opening throttle all the way. A 396 is a beast. Get it right and you will need to fill the bed with bricks to keep from smoking tires by accident.