Re: Need Gear Recommendation
 

My brother and I know that combo pretty well. My brother is the one responsible for the HP being at 287. And I now run a 74 vette with that same motor combo. As all of us know there are a ton of things that could cause your car to be off that much. I'm sure Charlie has you pretty close with the convertor. Michael Beard is right about the shift point. You can learn a lot from a play back tack. It would be easy just to say you are off HP but it would be nice to get more info on your engine. Any dyno numbers? Or any history on the motor? It sure sounds like you are off hp but you could have 4 or 5 things off a little that are costing you several tenths. The only reason at this point that I would change the gear ratio would be if I thought the ring and pinion was bad or set up wrong. The 538 may be faster in the end but if your 513 are set up right they will get you down the track a lot faster than your going. Make sure there not binding when the rear is warmed up. My Brother ran I/SA for the first couple of years in that combo and had 514 in the rear and went pretty fast with a lot less hp than he ended up with. Good luck

Re: Need Gear Recommendation
 

Have you had the engine & your carb and headers on the Dyno yet?
If so, scan the Dyno sheet and post it.
Based on the MPH your down of H.P.

When I ran my '74 Corvette I/SA car back in the '90's one of the things I learned with my engine was that the car was much quicker when:
1. Held the car at the line @ 1,500 RPM
2. Flat footed it on the last yellow
3. Made the 1st to 2nd shift @ 5,100 RPM
4. Made the 2nd to 3rd shift @ 5,500 RPM

When I made the switch from a Turbo 350 to a Turbo 200 my car picked up .20-.25

Back then my engine was just a home built adventure and only made 378 HP. It ran ok, but would not come close to running with the guys that had there packages all iron out.
At that time, a good friend and customer, Jeff Stealy (Rest in Peace) was a First Class Stock and Super Stock Engine builder. His engines of my combination which was a 350 with 882 heads,were making 420+ HP.

Other things to look at are brake drag.... you should explore everything, front to back, and make the car roll (push) with as little effort as possible.

Re: Need Gear Recommendation
 

No dyno yet, timing @ 39degrees, I will check the converter flash and as for brake drag coming back from the run , I could coast a good distance, but I will start checking the suspension and brakes as well, Thank you all so much. I know with all your expert advice I will get there. I will keep you posted, Any comments on the tire I should run.
Cam is a Bullitt
GRIND CHS311/315H106+4
> MASTERS H311/262 H315270C
> DUR @ .050 263/270
> LIFT .390/.410
> LSA 106
> INT C/L 102

Re: Need Gear Recommendation
 

See if you can borrow a set of 28inch Slicks to test this..

Dan

Re: Need Gear Recommendation
 

Interesting !!
My M/SA 1969 Impala ran a 350/255 with a Turbo and 3800 Stall Conveter.
Shift points were near identical.
Used 5.13s and 28 inch tire.
Woodro Built the Engine
Ran a best of 12.80 in WPB, Florida weather.
Before Woodro ran barely on to 3 tenths over the Index, mostly hot weather.

Always wondered how it would have done on a cold day?

D

Re: Need Gear Recommendation
 

Just put me under the bus because I had the HP hit.... LOL Lonnie I sent you a private message. Lots of good advice here, but I have been there and done that. Give me a call. Gary Parker

Re: Need Gear Recommendation
 

Isn't that a lot of timing?

Re: Need Gear Recommendation
 

Dan, Lonnie and Glen, though I have never tried (yet) shifting at 5100 and 5500 seems low for a small block that doesnt make tons of HP? You would be putting the load on the motor at that RPM and even a good SB would not be able to carry that load/weight? Use the multiplication of the gears, converter and trans to do some of the work.

Mr Parker have you ever shifted that low in your bad *** corvette? Will call you in a few days to catch up.

Re: Need Gear Recommendation
 

I lived in the Kansas City area back then, hot, sticky,humid...always bad air. In my Corvette I ran 4.88 gears and 28 x 9 MT Slicks.

Re: Need Gear Recommendation
 

[QUOTE=Joe DeMarzo;364299]Dan, Lonnie and Glen, though I have never tried (yet) shifting at 5100 and 5500 seems low for a small block that doesnt make tons of HP? You would be putting the load on the motor at that RPM and even a good SB would not be able to carry that load/weight? Use the multiplication of the gears, converter and trans to do some of the work.

QUOTE]
I know it sounds crazy Joe, but we tried shift points all over the place,I learned that with my engine, this worked. It would run to 7000 rpm in the lights, but we often wondered if I had put a 4.33 gear in it that it would have been even quicker.
Of course, that was then, and I had stock heads, not he 'good':rolleyes: stocker heads and intake. Back then there was 30-40+ more HP in the good heads and intakes :).