Looks like i'll be getting a 5.3 from another member here and I've seen some guys around here throw around the idea of making a 5.3 into a 5.7.

What will it take? Can I use ls1 internals? Going from 5.3 to 5.7 will I have to bore it out and leave the stroke alone?

I was thinking buying the crank, connecting rods and pistons "off the shelf" from an ls1 and installing them. Will this work or will I run into problems? Also what will be the effect of using the 5.3 heads with this set up?

Engine will be a DD with a mild cam and long tubes, not to crazy


Any input appreciated

 

All you need to do is have it bored. everything off of a LS1 will work, and the 5.3 heads will bump up compression a little bit, but they don't flow as well because of the little valves.

 

My brother has this setup in his 67 swb with a patriot 226 cam and it runs damn good.

 

You're describing exactly what I want to do! I'll be getting my 4L60e rebuilt with 'beefier' components pretty soon; then it's time to start planning to build an iron-block 5.7L

 

Well, if you going to buy crank, rods, and pistons then go for a 383.
if you want to save some cash then all you need is a set of LS1 pistons and
Have the block bored for a 5.7.
now you can add the 02 LS6 camshaft and the 243 heads for an iron block 5.7
That is rated for 405hp @ the crank.

 

I like your idea!! I think I'll go just with the pistons, bore it out, get the camshaft and heads and this should be enough for what my needs are. I doubt it will get sprayed or blown Oh yeah I forgot, FLT will be getting a call in a couple of months too

 

whats the biggest bore on a iron 5.3 can be made could it be bored to fit some 4.000 pistons with stock crank im try'n to make this happen also

 

max bore on a 5.3, 3.90 with a 3.62 stroke.

 

are the stock 5.3 rods are the same as the ls1 rods?

 

and can i bore the 5.3 iron to 3.905 bore and be safe .?