a lot of hate on the 5.3's take a look at turbo guys running boosted stock bottomend 5.3s its pretty impressive.

 

sry not reading it all but have u drivin a 6.0 gto???? wait for the 6.0 u wont be unhappy

 

if your going na do the 6.0 if your going boosted go 5.3! They have proven themselves over and over agian!

I out down 528hp and 491tq through a slipping 4l60e pushing a 9" with my budget 5.3 turbo setup!

I now have a th400 in it and bet its putting over 600hp to the wheels. Im expection mid to low 10's with a full weight Trans Am 3700#.

Funny you are doing an 88 mustang... Im getting ready to do a turbo 5.3 in my 88 mustang.. mine is gutted though, lol. You arent kidding they are light! 600hp in a gutted 88 mustang is gonna be crazy fast for only having $3500 TOTAL into it!!!!!!

 

Why hasn't anyone mentioned that a iron 5.3 bores out to an LS1 3.9" with no problems what so ever. So basically, you have an iron LS1 with no other changes other than a good set of pistons. I don't know what a good price is but a rebuildable 5.3 should be really cheap. Send your 5.3 heads to one of the many excellent port shops if you want to stay naturally aspirated. Bottom line is if your on a budget, a bored 5.3 is by far a cheaper starting place.

 

honestly I have seen some ls1 gto's pull the ls2 gto's... maybe the driver mod, but just sayin.

 

all these guys have good points but i'm just going to give you my opinion.......6.0

 

1) Buy the 5.3L
2) Bore it out to 5.7L

Just like that, you have an iron LS1 capable of holding boost...I don't have to tell you the next step, do I?

 

if your gonna go through the effort to bore a 5.3 you might as well just buy a 6.0 lmao! by the time you get the machine work done and new pistons you have more into that than what a whole 6.0 lq9 or lq4 costs and its iron block to! lmfao!

I say buy a 5.3 install some 317's, 02+ls6 cam, pushrods, springs... throw a bunch of boost at it and be done!!!!!