L03 engine, differences with TPI and TBI
11-06-2000, 12:15 PM
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L03 engine, differences with TPI and TBI
Originally posted by Pablo:
Exhaust and heads
We all know the TPI cars have way better exhaust manifolds and y pipes and catbacks
and it was suspected the heads were different
WELL, I have proof today
Our head casting number is 14102187, swirl port heads, extremely restrictive
a friend of mine (MrJ) with a 91 Trans am LB9 auto who runs some pretty fast times with very few mods (14.9@93) gave me his head casting number
#14101081
so its pretty much a given that L03 heads stink I think swapping to these tpi heads or the earlier #416 305 H.O. heads would unleash more than a few tenths.
Id really like to see someone bolt these on or the earlier #416's and just get headers and open element and post some times. I wouldnt be surprised if they were faster or the same times as an LB9 auto with headers and open element
either heads, the 081's or the 416's are a dime a dozen so why not look for a decent set and bolt em on?
Exhaust and heads
We all know the TPI cars have way better exhaust manifolds and y pipes and catbacks
and it was suspected the heads were different
WELL, I have proof today
Our head casting number is 14102187, swirl port heads, extremely restrictive
a friend of mine (MrJ) with a 91 Trans am LB9 auto who runs some pretty fast times with very few mods (14.9@93) gave me his head casting number
#14101081
so its pretty much a given that L03 heads stink I think swapping to these tpi heads or the earlier #416 305 H.O. heads would unleash more than a few tenths.
Id really like to see someone bolt these on or the earlier #416's and just get headers and open element and post some times. I wouldnt be surprised if they were faster or the same times as an LB9 auto with headers and open element
either heads, the 081's or the 416's are a dime a dozen so why not look for a decent set and bolt em on?
Originally posted by Dana92RS:
About the manifolds and y-pipe... The TPI exhaust manifolds were different than the TBI exhaust manifolds, with the TPI manifolds have larger 2-1/4" outlets. I'm pretty sure the TPI y-pipes were a larger diameter than the TBI y-pipes to match the outlets. Plus the location of the outlets is probably slightly different between the TPI and TBI manifolds so the y-pipe could not interchange anyways.
About the manifolds and y-pipe... The TPI exhaust manifolds were different than the TBI exhaust manifolds, with the TPI manifolds have larger 2-1/4" outlets. I'm pretty sure the TPI y-pipes were a larger diameter than the TBI y-pipes to match the outlets. Plus the location of the outlets is probably slightly different between the TPI and TBI manifolds so the y-pipe could not interchange anyways.
Also, the TBI engine # is L03, so what is the TPI engine number?? I want to be able to tell what type of heads I am getting from the wreckers, plus is there anyway to tell the TPI manifolds and Y-pipe apart from a TBI (L03) manifolds and Y-pipe?? Any other info would be appreciated.
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Godti
'89 Trans Am (Red)
305 TBI 5spd
[This message has been edited by Godti (edited November 06, 2000).]
11-06-2000, 03:32 PM
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y ou just posted the number for the heads above, they were the ones i posted
and i skimmed through but what i think dana said is that the manifolds and y pipe wont interchange like LB9 manifolds wont go with a LO3 y pipe
Unless you race in a "stock" class, dont bother with stock exhaust peices its a waste of time
and i skimmed through but what i think dana said is that the manifolds and y pipe wont interchange like LB9 manifolds wont go with a LO3 y pipe
Unless you race in a "stock" class, dont bother with stock exhaust peices its a waste of time
11-07-2000, 07:01 AM
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Originally posted by Pablo:
y ou just posted the number for the heads above, they were the ones i posted
and i skimmed through but what i think dana said is that the manifolds and y pipe wont interchange like LB9 manifolds wont go with a LO3 y pipe
Unless you race in a "stock" class, dont bother with stock exhaust peices its a waste of time
y ou just posted the number for the heads above, they were the ones i posted
and i skimmed through but what i think dana said is that the manifolds and y pipe wont interchange like LB9 manifolds wont go with a LO3 y pipe
Unless you race in a "stock" class, dont bother with stock exhaust peices its a waste of time
11-07-2000, 10:22 AM
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Ok, is there a difference in the L03 and LB9 bottom end?? (crank, cam, pistons, rods, etc....). If I bolted on the LB9 heads, and the TPI unit, would I pretty much have the LB9 engine???
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Godti
'89 Trans Am (Red)
305 TBI 5spd
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Godti
'89 Trans Am (Red)
305 TBI 5spd
11-07-2000, 01:53 PM
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Car: Trans AM
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Originally posted by Keith5:
The HO L69 305 had bigger valves, I don't know if both were bigger or just one. If you are going to swap heads onto your L03 rembmer that it has to be 87-92 and they have to be iron to fit your manifold, well you can get around that with some grinding.
The HO L69 305 had bigger valves, I don't know if both were bigger or just one. If you are going to swap heads onto your L03 rembmer that it has to be 87-92 and they have to be iron to fit your manifold, well you can get around that with some grinding.
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Godti
'89 Trans Am (Red)
305 TBI 5spd
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11-08-2000, 11:41 AM
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Car: Trans AM
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Anybody got an answer to my previous question?? Also, what is the difference between a LB9 and L69?? and the difference between the heads??
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Godti
'89 Trans Am (Red)
305 TBI 5spd
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Godti
'89 Trans Am (Red)
305 TBI 5spd
11-08-2000, 04:54 PM
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Ok, I'll take a shot but you better check it. The L69 was a carbed 305. The LB9 was a TPI
305. The later LB9 heads used center bolt valve covers while I think the L69 used the old style valve covers. I think the heads use the same size valves but the LB9 heads have a little better combustion chamber.I understand that the LB9
came in two versions, a 205 hp and a 230 hp
and I understand that the only difference is the cam.Thats my best shot, I hope someone can confirm and or improve this.....bob
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91 camaro RS convert
t-5
open element air cleaner
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3.42 Torsen posi
305. The later LB9 heads used center bolt valve covers while I think the L69 used the old style valve covers. I think the heads use the same size valves but the LB9 heads have a little better combustion chamber.I understand that the LB9
came in two versions, a 205 hp and a 230 hp
and I understand that the only difference is the cam.Thats my best shot, I hope someone can confirm and or improve this.....bob
------------------
91 camaro RS convert
t-5
open element air cleaner
TBI spacer
Flowmaster muffler
3.42 Torsen posi
11-09-2000, 06:14 AM
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RS is right
as i stated in my post, the L69 heads are #416 casting (last three digits)
they came on LG4s, and early LB9s too
they are similar to 081s, 416's have old style valve covers (perimiter bolt) and their combustion chamber is a little different
as i stated in my post, the L69 heads are #416 casting (last three digits)
they came on LG4s, and early LB9s too
they are similar to 081s, 416's have old style valve covers (perimiter bolt) and their combustion chamber is a little different
11-09-2000, 06:37 AM
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Car: Trans AM
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Thanks guys! so inorder to bolt up those heads to my 89 305, I would want the LB9's??
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Godti
'89 Trans Am (Red)
305 TBI 5spd
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Godti
'89 Trans Am (Red)
305 TBI 5spd
11-21-2000, 02:41 PM
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Car: Trans AM
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Originally posted by Godti:
Thanks guys! so inorder to bolt up those heads to my 89 305, I would want the LB9's??
Thanks guys! so inorder to bolt up those heads to my 89 305, I would want the LB9's??
11-21-2000, 05:07 PM
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Y ou can use either headset but if you use the 416's youll need perimeter bolt valve covers
and yeah, if you basically bolted on those heads, TPI unit, exhaust, youd have an LB9
and yeah, if you basically bolted on those heads, TPI unit, exhaust, youd have an LB9
11-25-2000, 01:57 PM
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I don't have a TBI, but I used to have a carb. My engine is a base LG4 with the centerbolt valvecovers (1987). All I did was convert to TPI with a few go fast goodies, and I turned a 14.97 @ 94.9.
Thats not to bad, considering I have the stock LG4 bottom end, heads, and exhaust manifolds.
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'87 Trans Am
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-->14.97 @ 94.9 MPH<--
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Thats not to bad, considering I have the stock LG4 bottom end, heads, and exhaust manifolds.
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If you live in Southeastern US, check us out!
South East Thirdgen
ASE Master Tech + L1
Savannah, GA
'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
JET AFPR,
Ported Plenum,
TB Coolant Bypass,
SSM SFC,
Boxed LCAs,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
KYB Shocks
-->14.97 @ 94.9 MPH<--
'97 Bonneville SSE
07-23-2014, 06:44 AM
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Re: L03 engine, differences with TPI and TBI
i just bought this motor and installed on my 86 trans am, my jw if a gen 1 motor 350 vortec heads from summit racing and intake would fit on this motor,mines a 93 model.heres the link plz let me know http://www.summitracing.com/parts/sum-151124
Last edited by snake006; 07-23-2014 at 06:47 AM.
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