Hi !

I would love to swap in a 400 cui Motor, in my 305 H.O. (L69) Firebird (1987).

The Engine would come from an old rusty Chevrolet G30 Van I can buy complete for like 1000$ (which is rater cheap for the country where I live)
Motor and Transmission are ok.

The only thing I am worried about, is that I cant find a lot of postings regarding to swapping in a 400 cui Small Block

The G30 is from 1977 with automatic Transmission and the owner wrote it has 280 HP


Can someone tell me if it would fit and what I will have to adopt ?
Would be great if someone can help me on with this

Thanks!

 

Yes it will drop right in. Your accessories will even bolt onto it.

Its oil dipstick will not fit with your exhaust manifolds; and you will need a different flex plate.

As far as any of us here know, the L69 was not available in these cars in 1987. Please post the 1st 11 digits of your VIN, as we'd all like to get any such facts that might be available.

However, that 400's HP output was NOWHERE NEAR 280. Here in the States, that motor was "rated" (for whatever small value those "ratings" have) at about 165 HP. It has very low compression and terrible heads, and of course, came with a 2-bbl carburetor. Totally NOT set up for "power".

Easy to upgrade that however.

 

Great!
Thats a good news to hear

Yeah, you are right..
My car used to be a LG4 V8 305... thats also what the VIN Says.
As the motor was worn out and the parts to fix and overhaul costed rather the same as the already overhauled & good running L69 from a friend of mine, I swapped this one in. Here its hard to buy a 350 or even a 400 cui Engine somewhere for that small money like you have it available.


Yep, thats what I read already.. read also a lot of troubles with cracks in the block when going into high rpm ranges and so on..

 

btw, that L69 used to be my 84's
imho as stated the 400 is not worth the hassle, but i'll gladly wait for some other inputs on that matter

 

so now the question back to sofakingdom:

Is it worth tuning the L69 for more torque
Or to swap and build up the Engine from the G30..

In an other forum I read that the "money vs power" you put into the L69 is the worsest compared to a 350, 383 or even 400..

 

The L69, while "the best" 305 of its day, is still ,,, ... just ..... a .... ,,,,,, ....... 305.

I'd do the 400.

Oh wait... can't .... already did... yanked the L69 out of my 83 car back in about 87 and put a 400 in it.

Think of it this way. The basic hot-rodding equation is:

Fun = Money x CID

Engine size MULTIPLIES your Money, in terms of the Fun it delivers. Money MULTIPLIES engine size. Or, to look at it another way, to get to any given level of Fun, then the more CID you have, the less money it takes. Or, for any given level of Money, the more CID you have, the more Fun you get.

Yes it REALLY IS that simple.

The 400 is DEFINITELY worth the hassle, but not just take it out of the van and jam it in your car. It's crippled by the way the factory set it up. However, if you put some decent heads on it (the ABSOLUTE MOST ESSENTIAL first modification to do) and a better cam, you'll be ASTOUNDED at what happens.

 

If your planning on building up one of those engines for more power, the 400 is the way to go. Every part you add will have more effect on the 400 vs the 305. Purchase the 400 and keep the 305 in the car until you build the 400 up a little.

 

The 400 small block will be the same size as your 305 or any other small block. There are no external differences.

This does not mean that it will be a straight swap, though. Your 87 Firebird has a computer that controls the engine and instrumentation. You will have to eliminate the computer and then reconfigure your gauges.

 

99% of the 305 setup will transfer over. He won't have to deal with deleting the ecm and issues related to that.

 

that's the main point. hunting it down over here is neither easy nor cheap, plus you have to throw a few k at it for it to be decent. that's why i swapped in the ls1.

the g30 in question is about $1k + $500 in transport.

 

.. and I have to mention, that I would rebuild, as already suggested, the engine and maybe also swap some parts when I am doing this, before I would swap it in.

my 305 is running good and I have all the time, space and $$ I need for this project

just could need a helping hand.. heh, ownor ? :-P


In the next two days I´ll receive the offers for the transport of the car to my place.
Depending on this and a visit at the current owners place, I will decide if I buy it or not.

But thanks to all of you!
You made my decision way much easier now


*edit*
# take note #
conclusion of sofakingdom´s comment: money x money ˛ = Wheel Stand Firebird *haha*

 

The gauges are unrelated to anything to do with the ECM , they run off senders in the engine that you just swap onto
any new engine