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crazy longhorn 01-11-2017 06:15 PM

LS build, parts questions
I know that this is not the LS side, but my questions are more to the side of parts manufacture. I plan to have a 5.3 bored 3mm & run a Mahle set of LS1 pistons (4032 alloy spec), for street use. My thoughts are, that if the crank passes magnaflux & cleans up .010/.010, It should be good for a 400 hp engine? The rods I question, as the mill is well seasoned (285,000 miles)! I dont want any junk from China in my Chevy ;) Any advise on rods & maybe a forged crankshaft, would be helpfull. Longhorn :chevy:

sprint_9 01-11-2017 10:13 PM

Re: LS build, parts questions
If all your doing is boring out, no forced induction I would just stay with new stock parts, maybe find what the best stock upgrade is and go with that.

Nick_R_23 01-12-2017 05:14 AM

Re: LS build, parts questions
If all you're looking for is 400 hp, your stock bottom end will hold up just fine. They've been shown to hold up to at least 1500 hp with twin turbos, and possibly more. Also, any particular reason for needing to bore out 3mm other than wanting LS1 pistons? Seems like a lot of wasted bores and money for a minor gain in cubes.

crazy longhorn 01-12-2017 01:32 PM

Re: LS build, parts questions
The idea of the 3mm overbore, is more for the thoughts of larger valves/ better heads. AFR looks to have a nice set of 210 cc street heads, but they will need a 3.9 bore to clear the 2.02/1.6 valves. Longhorn

sprint_9 01-12-2017 02:24 PM

Re: LS build, parts questions
Quite a few guys run stage 2.5 ported heads on an LS1 or 5.3 for that matter with good results. I think you can get a nice running engine reaching the numbers you want using more of a stock bore and use stock parts for way less money, just the savings in heads alone is quite a bit.

Here is a link on a set of those heads,

That link is for an outright set of heads, if your heads are decent enough you could send them in to save even more money if you wanted to.

Just an idea, not sure if you saw anything about this type of option.

crazy longhorn 01-12-2017 05:18 PM

Re: LS build, parts questions
Thanks for that link sprint_9 ! The flow # look good ,as does the pricing;) Still, they list the # with a 3.910 plate. Will that sized valves clear the stock or .020 over 5.3 bores? Longhorn

sprint_9 01-12-2017 09:06 PM

Re: LS build, parts questions
That 3.910 plate is referencing the flow bench they used to come up with their cfm numbers at a given lift.

If the only reason you are boring is to fit larger valves you might not even need to bore if your block checks out. I would still replace the pistons with that many miles but the rest might be good yet. Pick up a good used set of 243/799 heads and run them or have them ported and run the stock bore. FYI 799 heads come stock on many gen 4 5.3's. is a good source for used parts and info specific to ls stuff, not sure if you have been over there yet.

Before you buy or bore anything I would check things over and then call or email whichever company you use and lay out your plan and have them make some suggestions as well. Maybe your stock heads can be worked over, they will be able to tell you. When I bought my cam package it helped me make some decisions on lsa and lift. I bought my stuff from Texas Speed, but there are other places too.

Couple more links for you.

General Head info

This one has a stage one more suited for a stock bore, and stage 2 for ls1 bore

Set of ported 243/799 heads

crazy longhorn 01-14-2017 07:23 PM

Re: LS build, parts questions
Thanks again for the links....lots of info! It is time for me to open the old mill up, & have a look/see;) Anybody have any ideas on aftermarket con rods/vs bolts & resizing on the stockers? Longhorn

Dustytrix 01-14-2017 09:28 PM

Re: LS build, parts questions
I agree with Nick, you will be ok with stock rods and crank, best improvement would be the newer gen 4 floating rods.

clinebarger 01-15-2017 01:27 AM

Re: LS build, parts questions
Start with a 6.0L block, Bore it 0.30" & start with a 4.030" Bore!!

crazy longhorn 01-15-2017 07:39 PM

Re: LS build, parts questions
I like that idea the best Cline....guess, that I need to make parts out of another truck;) Longhorn

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