theroad64

So I have a bottom end knock that appears to be getting worse. I have found an Impala LT1 with 60k on it--$400.I want to replace my aging (165k) LT1 in my 93 Firebird with this motor.

Question: What, if any, are the BOTTOM END differences on the motor? Are they the same short block?

96capricemgr

Same shortblock yes. This would be a good opportunity for you to upgrade to the vented opti. Use your knock sensors and balancerand hub.

The Impala motor was the same as all the other b-body LT1s the lower HP rating was with 87 octane and comes with more torque at a lower rpm this is from heads and cam differences and makes it a much better match to the b-body than the f-body cam would have been.

biglope

I hate to tell you this but I am going to have to disagree with this. It is not going to bolt up correctly. You are going to nickle and dime yourself trying to get the right altenator brakets and other things. Will be a hassle unless you are looking to do the extra work.

I burn rice too

He already has all of the brackets. They'll come off his F-body LT1.

Go for it. You could even swap your aluminum heads and upgrade the cam since the engines already out and your getting such a screaming deal on the B-body engine. Rumor has it that those iron heads flow quite a bit more than the aluminum. So you kinda have two good choices.

Javier97Z28

Short block is good to go, go ahead and swap away.

I'd throw a cam in there and possibly your aluminum heads as well. You'll need your intake manifold to retain your 93 speed density and batch fire setup.

6SpdLT1Z

I agree

96capricemgr

The iron heads flow like 5% more, more but not a huge amount. To use your stock cam you would have to swap the good vented opti setup off the b-body motor in favor of your unvented on, definetely a step backwards. If you pull the cam out of the b-body motor go aftermarket. It would not be worth your while to swap the f-body cam in there. The IGNORANT here would have you believe the b-body cam is "bad" fact is some bolton b-bodies have topped 300rwhp and an armload of these heavy pigs are running 12s with boltons so this crappy little cam can't be too bad.

My opinion, drop in the whole stock b-body motor with it's vented opti and your accessories and intake manifold. Keep your aluminum heads set aside till you can afford to port them and do a cam. While your stock heads are the least flowing they are also the most desirable for porting.

Javier97Z28

I didn't see anyone in this thread bashing the impala variant LT1 cam in here. I noted it as a "while it's out" thing, thinking it was a good/cheap time to update, seeing as how he'd have to pull the intake anyways to swap back to his batch/speed density.

JDMZ28

Dude think about it like this> change the heads aluminum, saves weight, and a cam swap, maybe 200 bucks. Other than that look at it as a deal.

RedLT4Mike

I agree that this is a good strategy.

You'd save money on those "nickle&dime" things that are really $20-$60.

theroad64

I plan on using my OEM aluminums, with possibly a HotCam or CC305, nothing big. Just checking to see that no major differences existed--and I hadnt even thought about the vented opti--definitely a plus.