1969 Corvette Stocker

X-TECH MAN · 08-08-2009, 11:27 AM

Quote:

Originally Posted by S/ST4707

If you were building a 1969 Corvette for Stock what engine combination do you think would be most competitive? Also, if you were to go to a big block which combination would have available head and manifold castings.

If it was me just starting out in stock I would go with the 300 HP version. It has been de-rated to 290 HP and the 69 Corvette coupe breaks (10.87) good for F and G. Going to E might be tuff although the car can get really light. The one I ran back in 1970-72 could get to 2950 lbs with steel cragar spoke wheels on the front and the OEM ralley steel wheels on the rear. This was with the radio, heater, windshield wipers, etc. still in the car and I had to carrry the steel wheeled spare tire and some balist to make weight (3152) as we couldnt go to the min. weight back in 1970.. Its a less expensive combo to assemble and you can still get away with the swing axle assembly with an automatic (Turbo 350 or 200 metric= less weight). We had to use a 400 turbo back in the stone age although mine was a 4-speed (muncie). If you beef up the rear axle assembly with larger u-joints and a 12 bolt ring and pinion (cut down to fit the 10 bolt rear) it will live. The big blocks really need the 12 bolt conversion although some are getting away with the swing axle (pure luck) with an automatic. If money is no object then Id build an L-88 for AA and A with an automatic. A 12 bolt solid axle would be mandatory with the big "KHAHUNA" All of the engine combos are set back in the chassis approx 10% and the wheelbase is only 98 inches. GREAT for a race car. Its one bad Mo Fo. Those Mustangs wont keep their HP rating forever as some inflated egos will come into play sooner or later. Its all a mater of how fast do you want to go and how much do you want to spend.

S/ST4707 · 08-08-2009, 03:50 PM

Thanks for the input and suggestions. I really am looking at the Corvette due to engine setback. The only drawback I see is the use of a transverse spring with a solid rear and short trailing arms.

Chad Rhodes · 08-08-2009, 08:13 PM

Quote:

Originally Posted by S/ST4707

Thanks for the input and suggestions. I really am looking at the Corvette due to engine setback. The only drawback I see is the use of a transverse spring with a solid rear and short trailing arms.

shoot me an private message and I will try and help you out with the IRS, and I can also recommend someone to do the straight axle conversion if thats the route you want to go.

Chad Rhodes · 08-08-2009, 08:09 PM

Quote:

Originally Posted by X-TECH MAN

If it was me just starting out in stock I would go with the 300 HP version. It has been de-rated to 290 HP and the 69 Corvette coupe breaks (10.87) good for F and G. Going to E might be tuff although the car can get really light. The one I ran back in 1970-72 could get to 2950 lbs with steel cragar spoke wheels on the front and the OEM ralley steel wheels on the rear. This was with the radio, heater, windshield wipers, etc. still in the car and I had to carrry the steel wheeled spare tire and some balist to make weight (3152) as we couldnt go to the min. weight back in 1970.. Its a less expensive combo to assemble and you can still get away with the swing axle assembly with an automatic (Turbo 350 or 200 metric= less weight). We had to use a 400 turbo back in the stone age although mine was a 4-speed (muncie). If you beef up the rear axle assembly with larger u-joints and a 12 bolt ring and pinion (cut down to fit the 10 bolt rear) it will live. The big blocks really need the 12 bolt conversion although some are getting away with the swing axle (pure luck) with an automatic. If money is no object then Id build an L-88 for AA and A with an automatic. A 12 bolt solid axle would be mandatory with the big "KHAHUNA" All of the engine combos are set back in the chassis approx 10% and the wheelbase is only 98 inches. GREAT for a race car. Its one bad Mo Fo. Those Mustangs wont keep their HP rating forever as some inflated egos will come into play sooner or later. Its all a mater of how fast do you want to go and how much do you want to spend.

I beg to differ on that. A properly set up Swing Axle will live behind a big block just fine. Greg Eaton runs mid to high 8's on a Tom's differential IRS. You do have to know what you are doing but the Tom's stuff is 100% reliable in a stocker. Its also an advantage on a marginal race track.

Rich Biebel · 08-08-2009, 08:26 PM

I recall the issues with the IRS Corvette rears a little. When Bernie Agamen built his Corvette he was given an ok to use a std solid rear axle. When he showed up at the racetrack the story changed and he had to change it back to the IRS type rear. He broke that thing numerous times as I recall. Now that was a big tire car and a 454 but they were not all that fast back then compared to today's stockers. I was pitted next to Muni Haddad at Maple Grove one year and they were workjing on the rear of their Corvette. I was wrestling with my own issues but on his next run Haddad crashed that car badly and went up and maybe over the guardrail. I heard it was a half shaft failure......I'd be hesitat to race one if it had a BB without using the solid rear...

Personnaly I'd run the 350/300...Cam is pretty small but hey scads of guys run that cam and go fast with low compression 350's...Same cam.....Those cars are nice and make very nice racecars. There is a '68 327 for sale on this site I think.....Real nice loooking car.....

Bob Bender · 08-10-2009, 04:05 PM

[quote=Rich Biebel;134033]I recall the issues with the IRS Corvette rears a little. When Bernie Agamen built his Corvette he was given an ok to use a std solid rear axle. When he showed up at the racetrack the story changed and he had to change it back to the IRS type rear. He broke that thing numerous times as I recall. Now that was a big tire car and a 454 but they were not all that fast back then compared to today's stockers. I was pitted next to Muni Haddad at Maple Grove one year and they were workjing on the rear of their Corvette. I was wrestling with my own issues but on his next run Haddad crashed that car badly and went up and maybe over the guardrail. I heard it was a half shaft failure......I'd be hesitat to race one if it had a BB without using the solid rear...

The half shift broke in the lights............he went a long way on his top......but he was "OK"..........

X-TECH MAN · 08-08-2009, 08:59 PM

Quote:

Originally Posted by Chad Rhodes

I beg to differ on that. A properly set up Swing Axle will live behind a big block just fine. Greg Eaton runs mid to high 8's on a Tom's differential IRS. You do have to know what you are doing but the Tom's stuff is 100% reliable in a stocker. Its also an advantage on a marginal race track.

I had the "TOMS" complete swing axle also known as Henerys stuff. I got all of mine from Leon Maranian when he went to S/S and a dana rear. It is really strong but your not supposed to run a spool...Just a posi unit with a swing arm assembly (NHRA rules) though some do run a spool. Several have ended up in the wall because of using a spool instead of a posi (Muni Haddad for one???) when a half shaft or U joint breaks look out.. Your on borrowed time with a high HP big block. Its up to you. If i was going with the small block I would stay with the swing axle. I ran mine for 3 years with a small block and a 4 speed (7 inch tire days) with out a failure but as soon as we went to the S/S rules of 1972 (larger rear tires) I ran into breakage. One tip....align the rear with 1/8th degree Positive camber with the swing axle and use a heavy rated (pound) transverse spring.

Chad Rhodes · 08-08-2009, 10:33 PM

Quote:

Originally Posted by X-TECH MAN

I had the "TOMS" complete swing axle also known as Henerys stuff. I got all of mine from Leon Maranian when he went to S/S and a dana rear. It is really strong but your not supposed to run a spool...Just a posi unit with a swing arm assembly (NHRA rules) though some do run a spool. Several have ended up in the wall because of using a spool instead of a posi (Muni Haddad for one???) when a half shaft or U joint breaks look out.. Your on borrowed time with a high HP big block. Its up to you. If i was going with the small block I would stay with the swing axle. I ran mine for 3 years with a small block and a 4 speed (7 inch tire days) with out a failure but as soon as we went to the S/S rules of 1972 (larger rear tires) I ran into breakage. One tip....align the rear with 1/8th degree Positive camber with the swing axle and use a heavy rated (pound) transverse spring.

Well dad's been racing IRS vettes since 1970, and we have had zero failures since we went to the Tom's stuff. I also know Leon pretty well. If you really study the forces and physics behind these rear ends its not a big issue. The Tom's 1480 stuff is damn near bulletproof if you follow a few rules. Hint: the car shouldn't "squat".

Oh and about the spool issue. ANY car would do that if it broke an axle with a spool. The big issue is the outer axle and the Henry's/Tom's/Peppy's/etc solved that. Regular maintenance, and some good knowledge of geometry and physics goes a long way on these cars.

S/ST4707 · 08-09-2009, 04:21 PM

Guys, Now have finally decided to build a car I will go to a solid rear end. Chad, I will PM you to find out who you recommend for the solid rear end. Thanks for the input.

KEN BUGAJ · 08-10-2009, 04:25 PM

Quote:

Originally Posted by Chad Rhodes

I beg to differ on that. A properly set up Swing Axle will live behind a big block just fine. Greg Eaton runs mid to high 8's on a Tom's differential IRS. You do have to know what you are doing but the Tom's stuff is 100% reliable in a stocker. Its also an advantage on a marginal race track.

Tom's stuff would be the way to go.
You'll never get the 427/400 3X2 to run with the Camaro's
The 390 Hp has a problem with the intake, It's junk.
If I were to do another Corvette it would be with Tom's stuff and the L-88 Automatic,
We ran SS corvettes year's ago with Tom's stuff, It held up to 700 hp plus.
Why put the solid rear in a Corvette and make it like a Camaro.
You take the best part of the car away.
With the 502's in Top Stock Matt Morgan and I had the same HP.
He always ran the same ET but I would run a bit more speed. (I had a 12 bolt solid rear)
I have the feeling the IRS would run a bit quicker.How much, That's the question.

08-08-2009, 03:50 PM	#2
S/ST4707 Junior Member Join Date: Nov 2006 Posts: 23 Likes: 0 Liked 0 Times in 0 Posts	Re: 1969 Corvette Stocker Thanks for the input and suggestions. I really am looking at the Corvette due to engine setback. The only drawback I see is the use of a transverse spring with a solid rear and short trailing arms.

08-08-2009, 08:26 PM	#5
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,314 Likes: 25 Liked 544 Times in 213 Posts	Re: 1969 Corvette Stocker I recall the issues with the IRS Corvette rears a little. When Bernie Agamen built his Corvette he was given an ok to use a std solid rear axle. When he showed up at the racetrack the story changed and he had to change it back to the IRS type rear. He broke that thing numerous times as I recall. Now that was a big tire car and a 454 but they were not all that fast back then compared to today's stockers. I was pitted next to Muni Haddad at Maple Grove one year and they were workjing on the rear of their Corvette. I was wrestling with my own issues but on his next run Haddad crashed that car badly and went up and maybe over the guardrail. I heard it was a half shaft failure......I'd be hesitat to race one if it had a BB without using the solid rear... Personnaly I'd run the 350/300...Cam is pretty small but hey scads of guys run that cam and go fast with low compression 350's...Same cam.....Those cars are nice and make very nice racecars. There is a '68 327 for sale on this site I think.....Real nice loooking car..... __________________ Rich Biebel S/C 1479 Stock 147R Last edited by Rich Biebel; 08-08-2009 at 08:34 PM.

08-10-2009, 04:05 PM	#6
Bob Bender VIP Member Join Date: Jan 2009 Location: Maryland Posts: 1,733 Likes: 1,599 Liked 459 Times in 90 Posts	Re: 1969 Corvette Stocker [quote=Rich Biebel;134033]I recall the issues with the IRS Corvette rears a little. When Bernie Agamen built his Corvette he was given an ok to use a std solid rear axle. When he showed up at the racetrack the story changed and he had to change it back to the IRS type rear. He broke that thing numerous times as I recall. Now that was a big tire car and a 454 but they were not all that fast back then compared to today's stockers. I was pitted next to Muni Haddad at Maple Grove one year and they were workjing on the rear of their Corvette. I was wrestling with my own issues but on his next run Haddad crashed that car badly and went up and maybe over the guardrail. I heard it was a half shaft failure......I'd be hesitat to race one if it had a BB without using the solid rear... The half shift broke in the lights............he went a long way on his top......but he was "OK".......... __________________ Bob Bender 144 O/SA 2010-2012 National Record Holder

08-09-2009, 04:21 PM	#9
S/ST4707 Junior Member Join Date: Nov 2006 Posts: 23 Likes: 0 Liked 0 Times in 0 Posts	Re: 1969 Corvette Stocker Guys, Now have finally decided to build a car I will go to a solid rear end. Chad, I will PM you to find out who you recommend for the solid rear end. Thanks for the input.