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Series II to Series III swap



Fivefingerdeathpunch said:
3800 = 3800?

You just have to know which block you have. Not that is matter for a swap, but for what mods you may run.
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Yes, 3800 block. Its in regards to dropping a series 3 into a firebird 5 speed and I feel that if they are the same 3800 with the same bolt pattern that the series 3 should fit onto a 5 speed firebird
 


it doesn't matter which you have a 3800 block is all the same whether if its s/c or not, but if you have an engine in mind and the trans just happens to be a 4t65-e HD then your all good to go
 
A Series III block says Series II on it for the info of all in this thread. Reason...the block is the same, GM didn't even waste the money to change the casting of the block.

Series II and III share the same exterior everything for bolt holes, locations etc etc. A few accessories may look different, in those cases bolt your accessories on. When using either SC or NA Series III in a car that had a Series II, you will need a TB adapter.
 
crzystve42 said:
Yes, 3800 block. Its in regards to dropping a series 3 into a firebird 5 speed and I feel that if they are the same 3800 with the same bolt pattern that the series 3 should fit onto a 5 speed firebird
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I'm sorta confused on exactly what your doing but from what I gather you are putting a series 3 s/c engine into a firebird that was originally a series 2 n/a. IIRC I remember hearing something about the firewall needing some modification to clear the supercharger case.

zenman400 said:
it doesn't matter which you have a 3800 block is all the same whether if its s/c or not, but if you have an engine in mind and the trans just happens to be a 4t65-e HD then your all good to go
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It's not gonna be a 4t65e. Firebird is rwd w/ a v6 it'll have a 4L60E if auto or a borg warner 5 speed if manual

Also HD is irrelevant as both HD and non HD trans use exactly the same case
 
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there in fact a difference. The 4t65 is a bit shorter and obviously it has a different stock final drive gear ratio and also different gearing thru the four speeds. The HD final drive is 3.29 and a car like mine which is a base model has a 3.05. Oh yes, I forgot to mention what makes an HD a HD, the better differential. ZZP sells the upgrade along with the rebuild kit for the 4t65.
 
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