Can anyone tell if these are stock?

[GTX MATT]

Those are TRW 2293s, you're probably around 11:1 with 906 heads if the heads are uncut. If it runs good don't worry about it. If you change them out and want to sell them give me a holler. I believe those were advertised as 11.5:1 or 12:1, either way they wont make that on a non blue printed 383 with uncut heads. If you've got a healthy cam you may not have any issues.

I believe they came in stock bore, .030, and .060 over. If you want to know if the engines been bored out why not just measure with some verniers? 4.25 is stock, 4.28 is .030 over and 4.31 is .060.

 

[Cranky]

If the exhaust is pretty loud, you might not here any pinging. If it is and bad enough, it will usually burn off the spark plug ground strap but light pinging will also so up on the plugs and there are a lot of vids and info on the net that explains how to read plugs. There are also several ways to help a pinging engine to not do that. An engine that runs at 195 will have a tendency to ping while one that's at 180 might not. Spark plug heat range might be too hot. High compression engines generally don't like standard plugs. Reduce the timing some can help too. A lean running engine will also ping before a richer one will....

 

[bandit]

Thanks guys! I looked up a pic of the TRW 2293 and I think you nailed it. The ad I saw said they were 11.5:1. If I ever pull the heads again I'll def take a measurement.

I have pulled plugs a few times and if anything, these are running rich. Timing is backed off some.

"Keep the wheels a spinnin' and the girls a grinnin'." lol

Thanks everyone for the input on this. I have learned a ton of info I never knew. Hope I can return the favor to all of you some day.

 

[GTX MATT]

Bandit, how backed off is the timing? If you can run 32 degrees of total timing without detonating I'd say its really not too bad. Way better than the guys with 7.5:1 383s who have done everything to try to make them run decent but they pull like a 400 Corodoba!

 

[moparsteve636]

P.M. sent to GTXMatt

 

[bandit]

I am not positive what the actual timing is. I have never trusted the timing mark on the engine. It reads 15 before tdc right now with a timing light on it. (this higher compression may be why it is off??) I timed it by advancing it until the starter labors then back it off until it starts and I have no ping on full throttle. The reason I say it is retarded some is because I had to back it off a few times to get rid of the initial ping. I could be off stating how much if at all it is retarded though. Just my assumption.

 

[GTX MATT]

Bandit, I'm not surprised you had to back it off to get rid of the ping, it was probably quite a bit of total timing if it had enough initial to fight the starter and the distributor hasn't been recurved.

To check the total timing all you need to do it rev the engine until the timing stops advancing and see what it is. This will probably be in the 3000-4000 RPM neighborhood if the distributor hasn't been recurved. I usually get a helper and tell them to rev it to 3000. Then I have them rev it to 3500 or 4000. If it doesn't change between 3 and 4 its safe to assume its all in.

What are you running for a distributor?