2.8L to 305 Can it be done???
2.8L to 305 Can it be done???
Hi I am asking this for my friend who has a Firebird. It has the Gutless 2.8L V6 and he wants to upgrade. I can get a 305 fairly cheap so he was pretty interested in throwing that in. I know the wiring harness is shot on the 305 but we were thinking early 80s or even 70s Carburated as to avoid some of the ECU BS. I think I read that the tranny wont work but we can fix that. With a new one. My main question here is will the 305 drop right in or are we going to have to fab up mounts??? We are looking to do this as cheap as possible and we both have some mechanical background so if its a direct bolt in that would make things so much easier. Thanks Bob
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Joined: Sep 2008
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From: Olivebridge, NY
Car: 92 Formula 350
Engine: L98
Transmission: TH700R4
Axle/Gears: 3.23 posi
Re: 2.8L to 305 Can it be done???
pretty sure there have been countless threads discussing this stuff. do a
and you should find out everything you need to know
and you should find out everything you need to know Supreme Member
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Joined: Sep 2006
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From: sunny so cal.
Car: 1990
Engine: 305
Transmission: 700r4
Axle/Gears: stock
Re: 2.8L to 305 Can it be done???
well im sure you can bolt two more cylinders onto it. or you can buy a zz4 ls crate engine and do it right.
Re: 2.8L to 305 Can it be done???
Hahaha Thanks guys I did a little searching I will have to dig deeper. The goal is cheap here not Crazy expensive. I searched about and most of the threads are 305 to 350. I guess its safe to assume it bolts in then.
Last edited by Bob08; Apr 4, 2009 at 01:52 PM.
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Joined: Feb 2009
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From: central Louisiana
Car: 88 Firebird T-Top
Engine: 350 crate
Transmission: 700r4 w/shift kit
Axle/Gears: one's that move the car
Re: 2.8L to 305 Can it be done???
change the motor mounts out and move them forward to the other holes..will need v8 mounts..also where are you located i have motor and tranny
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Joined: Feb 2009
Posts: 183
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From: central Louisiana
Car: 88 Firebird T-Top
Engine: 350 crate
Transmission: 700r4 w/shift kit
Axle/Gears: one's that move the car
Re: 2.8L to 305 Can it be done???
no i'm putting a turbo on my 6 and have a rebuilt 305 i don't need..if you want to know about tuboing the 6 look at the stickys thread in the v6 forum..gives step by step stuff there
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Joined: Mar 2000
Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Re: 2.8L to 305 Can it be done???
Ok so here is were its at. I found a running mid 70s 350 for 300 dollars. I was also told to get a 700R4 tranny for it. I was telling the guy my plan about wiring harnesses and all that B.S. and he said the 700R4 was completely mechanical. This would be sweet. I know I need to change the sending unit in the tank to accept the manual pump. This would be so easy to do from the sounds of it.
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Re: 2.8L to 305 Can it be done???
Ok Thanks for clearing that up he didn't tell me that. For the money and the ease of Installation you think this would be the easiest to do for first time swappers. I have some experience wrenching but have never done a motor swap.
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
I would say swapping a 350 into a '70 Nova that originally came with a straight six is a lot easier than this.
But, that doesn't mean it's particularly difficult. Certainly easier than an LS1/T56 swap (having done both).
But, that doesn't mean it's particularly difficult. Certainly easier than an LS1/T56 swap (having done both).
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Joined: Sep 2008
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From: N.C.
Car: 1989 Camaro
Engine: building a 350
Transmission: TH350
Axle/Gears: soon to be 4.10 non posi
Re: 2.8L to 305 Can it be done???
im just finishing this exact swap and to be totally honest its a bit more involved than you might think. I wouldnt recommend it if you dont have a lot of spare time, patience, patience, patience, patience and beer.
Junior Member
Joined: Sep 2008
Posts: 59
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From: N.C.
Car: 1989 Camaro
Engine: building a 350
Transmission: TH350
Axle/Gears: soon to be 4.10 non posi
Re: 2.8L to 305 Can it be done???
don't let the amount of work discourage you from doing it, It is time consuming but the payoff will be worth it
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Joined: Sep 2006
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From: chattanooga,tn
Car: 85 z28
Engine: 355ci
Transmission: th400
Axle/Gears: 3.73
Re: 2.8L to 305 Can it be done???
You seem to have all the answers so I'll just ask you (that's a complement btw and not sarcasm). Doing a 2.8 5sp swap to a 350 tbi 4l60 swap....will the driveshaft work and if not will a stock 700r driveshaft work?
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Re: 2.8L to 305 Can it be done???
I still plan n giving it a go. all I am waiting on is him. He still doesn't know what he wants to do yet. Its money thats playing a factor also. I can get the 350 for 300 but I still need a tranny. Once those are had then everything should be pretty cheap.
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
As stated in the sticky, the best way to approach this is with a complete V8 donor car. I picked up my V6 car with cracked block in early May, looked around for an engine for a month and ended up with the LG4/TH700 donor car in early June. Got it running in August.
But, then, I pulled the LG4 out of Berlinetta #2 in Feb '08, and the LS1/T56 still isn't running.
But, then, I pulled the LG4 out of Berlinetta #2 in Feb '08, and the LS1/T56 still isn't running.
Re: 2.8L to 305 Can it be done???
Ya a donor car would be the best bet. I just dont know were we can find a cheap fire bird with a 350 in it. I mean they are nice cars and they are gonna be expensive.
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