small block chevy timing.

forvicjr, your engine is unique, the Vortec heads were never factory on a SBC 400. They are a very good head up to 5,500 RPM. In many tests they hold their own against AFR, Dart, Edelbrock and many other quality aftermarket heads.
The Vortec uses a small chamber with a very good design. You will find a Vortec design maxes power at about 28 degree's total timing.

If you were running other design heads the GM small blocks perform best with 36 degree's approximately. Some use 1 or 2 more or less depending on the combination. Hypereutectic pistons are very popular today and they reflect more heat into the chamber, the extra heat reflection will have you backing the timing off 1 or 2 degree's compared to a forged or factory cast piston.
The Vortec head is the best factory flowing small block GM head ever built even though it runs 1.94 intake valves and 1.5 exhaust but with your 400 inches you will max the head around 5,500 RPM.
Because of the small chamber used in the Vortec heads you will have very high compression unless your pistons use a deep dish design I would bet you are actually at 10.5:1 or more.
The 5.7 Rod combo really helps your 400 internally, it takes a lot of side load out of the piston and free's up power and efficiency.
Hope you get to enjoy it. .040 over, so you are running a 408. Big engine, nice, I bet it pulls like a freight train.

forvicjr wrote: Tim the bent shaft went with my buddy to his work. He is a cnc supervisor. He put it on a machinist table and said that he couldnt get a three thosandths shim under it anywhere. I installed in the boat and found later that was bent just aft of the log.

Vic,
It sounds like your supervisor friend needs some training! The best way is not on a "machine table" as you call it. Hopefully it was a granite surface plate. Properly, you set up the shaft in V blocks, put a dial indicator on it and rotate the shaft. Aft of the strut on the taper is very common due to prop hits especially if there is too much shaft between the prop and strut. WHY didn't your friend check the shaft at the taper???

8122pbrainard wrote: forvicjr wrote: Tim the bent shaft went with my buddy to his work. He is a cnc supervisor. He put it on a machinist table and said that he couldnt get a three thosandths shim under it anywhere. I installed in the boat and found later that was bent just aft of the log. Vic, It sounds like your supervisor friend needs some training! The best way is not on a "machine table" as you call it. Hopefully it was a granite surface plate. Properly, you set up the shaft in V blocks, put a dial indicator on it and rotate the shaft. Aft of the strut on the taper is very common due to prop hits especially if there is too much shaft between the prop and strut. WHY didn't your friend check the shaft at the taper???

Pete. Glad to hear from the grumpy ole man.lol I told him to check it and that how he did it. He is very anal and I think it was ok. I think something happened to it during the stringer replacement after he checked it. It was sitting around in the shop and could have gotten damaged in that time. I found it by holding a sharpie against the hull at the log and rotated the shaft. The marker showed a high spot half way around the shaft.After seeing that I seen no need for a dial indicator. This I think he would have spotted on the " granite surface table" lol

I dono pete. Where the bend is would be right smack in the middle of the shaft. Roll the thing across the table and it would be hopping around like a rabbit. Seriously I never measured it but im sure you would be stacking many feeler gauges to measure it. Any way its fixed now. Still a mystery though. Im not convinced he missed it. And the boat didnt vibrate before the stringer replacement. Hell who knows lol.

Whatever gets the job done...lol...:-D