I was thinking about doing the tpi swap on my 1991 camaro 305 TBI. I was wondering if there were any differences in the two 305's as far as cam and heads go. Thanks a lot.

 

A search will afford you a wealth of information. Cams differ on the lb9 (305 TPI) dependent on rear end and transmission. But to give you a basic answer, they are nearly completely different engines all together. 170hp for the l03 was kind, 215 for the lb9 sometimes seemed a bit reclined.

 

I did search and i couldn't find exactly what i was looking for. I did seaarch on the internet for a long time today and i came up with this. Camaros with a 305 5 speed and a 305 auto had the same cam. if you had a 305 with the G92 option and a 5 speed you got the same cam that is in the L98. So if i have this correct there is a version of the LB9 that is basicly the same engine as mine with TPI and makes about 200HP. I also looked at the head situation and the info i found said that the LO3 and the LB9 have the same cumbustion chamber and the same size valves. However the GM parts numbers are different. Does anyone know why? I just want to have an idea of what the TPI swap will give me and i want to know what will make me have pretty much a LB9 to work with. Thanks for any help.

 

The heads are very different from the lb9 to the l03. I have seen lb9's that can be woken up, but l03's just plain suck. Do a search on l03 heads. Honestly if you want a good swap and you want to do it cheap, you can get an l98 for a bit more than a lb9, especially on ebay. Though if you already have a 305, it is cheaper in most cases to build for power than build a 350 (trust me just put over $5k in my 355, though Ill have 450hp)

A lot of people on these boards will bash the 305, but I personally like the lb9. It wakes up to mods and you can easily be making 300hp range with simple bolt ons, maybe more if you want to get real creative. Basically how much money do you have to spend and how much power do you want to make. If you want 300hp, build the lb9, if you want anything more than that go with something bigger (383, 408, 454) or go unique LT1, Ls1 or :hail: LS6

 

I was planning on converting the L03 to TPI so i could run a vortech supercharger. I have thought about building a L98 from scratch, but i'm starting school soon and i don't know if i'll have the time. I thought this supercharged set up would be a nice way to make some good numbers and not have to do a complete swap. Maybe i should just find a L98 short block and start working. I would like this car to have 250-300 HP and be CA smog legal. I just thought with the specs i saw on the L03 vs. the LB9 that i could convert and then add the supercharger. From what you are saying this is a bad idea. making decisions is hard. thanks for the help.

 

I would definatley swap the engine. I looked at swapping my LB9 for an L98 then decided that I would go with a 383 instead. I will supercharge that instead.

:hail: Supercharged TPI 383 (Aftermarket intake of course!)

You could pick up a LB9 305 in the classifieds section for next to nothing. If all you wanted was around 300HP or so. Then you could supercharge it if you wanted to.

 

Remember to supercharge in an engine you want to use 8.5:1 at most, maybe 9.0:1 with a aluminum headed engine. The stock lb9 would not last long if you just dropped a supercharger on there. Go check out willie's ride if you want to know how to build a supercharged 305... otherwise just build the 305 to 300hp and you'll be set

 

so it seems like the the best way to do this is a complete swap. Now i have to decide if i want the 350 or if i want to make a 305. I'll check out my options as far as finding a short block go. Thanks for the help.

Sam

 

No problem. Good luck.

James

 

Sorry to bring this back from the dead, but I got some questions about this too. I currently swapped the L03 out of my 1989 Camaro RS and replaced it with a '89 L98. Then I converted the 89 L98 to speed density (different TPI intake and all) and put in an aftermarket cam. Now I am left over with the following parts:

'89 L03 complete motor
'89 MAF TPI Setup (with 165 ECM and ability to make my own LB9 chip)
Painless MAF TPI standalone Harness
L98 Cam
'89 700r4 tranny

I would like to convert the old L03 to a LB9 (with L98 Cam) and put it in my older S10 along with the 700r4. From what I've read, the only part I need to do the LB9 conversion that I dont have is the LB9 heads. Is this correct? Anything else I'll need to convert a L03 to a LB9? I'm not looking for all out performance here, I want torque for towing purposes.

Thanks!