Hey all, over from tech looking for some info on the 5.3 iron block. Im already H/C/E makin a good amount of power but Im starting to look for a new project/engine build. Ive seen the 5.3's for cheap (~$100) and alot more people lately have been going the 5.3 route.

Ive read that the 5.3's are similar to the LS1 in that the most you can bore them to is 3.905, that with a 4.125 crank would make 396, which would be pretty cool and I would think make good power. Been looking around for the last couple hours and here is the current parts list;

Block: 5.3L Iorn block $100-$200

RODS: Eagle SIR6250BBLW 6.250" $305.33

Crankshaft: K1 Crankshafts (By Carrillo) 346-4125RB6F 4.125Stroke $785
SCAT Chevy Forged 4340 4-LS1-4125-6125-24 4.125Stroke $699

PISTONS: Diamond/Mahle forged 3.905bore +/- 600 dollars

Im just looking for some of the guys who have experience with the 5.3 strokers, how well they work and how sane this project sounds. Thanks guys!

 

I think the largest you can stroke the 5.3 block is to a 383 cid displacement. Not 100% sure though.

 

So the 5.3 cant be bored the same as an LS1? I know a couple guys with 396 LS1's that love em. I was told the 5.3 was the same but thats why Im here!

 

it can be bored to ls1 specs, but I beleive i read somewhere that there would be clearance issues if you went with a longer stroke than a 383 crank.

 

Yep you can get a ls1 bore with a stroker crank for 383. the 5.3 is similar, but not exactly the same as an ls1.
I would also look into some 6.0l blocks, for a few hundred more you can snag one of those for a better starting platform

 

the 5.3 is the same block as the ls1 but with a smaller bore and it is cast. they can take the same max bore. a 4.125 crank should fit. might need to do a little clearencing in the block. and move the windage tray away from the crank. i was going to do this but never got the crank and changed my mind. and a 3.905 bore with a 4.125 stroke would be 404 cid.

 

and those rods are too long the pistons would have like no comp hight.

 

Wow 404 really? So what would 396 be?
Has anyone here taken a 5.3 out that far? Numbers?
I would look for a 6.0 but around here they are going for around a grand, where the 5.3's are like 200 bucks max.

So the 3.905 is doable? Would reliability be an issue at this point?
Thanks for the input fellas!

 

So what would you reccomend?

 

i was going to go 3.903 but the 3.905 would be fine.not sure on the 396.