Head decision for 5.3 NA build.
01-10-2018, 12:48 AM
#1
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Head decision for 5.3 NA build. I have a clean 5.3 block I'm rebuilding at stock bore size with flat top pistons for a reliable NA build to drop in my 76 trans am.
I have 862 heads, I can use but don't know if they're the best option. Are they worth getting ported for my purposes or are aftermarket casting the better option?
I have 862 heads, I can use but don't know if they're the best option. Are they worth getting ported for my purposes or are aftermarket casting the better option?
01-10-2018, 02:29 AM
#2
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Unless you want to go aftermarket, a good valve job and moderate porting of your 862 is likely your best bet
01-10-2018, 07:53 AM
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absolutely
I'm also considering a 4.00 crank in the build so I want to make sure these will flow enough in ported form.
I'd like 4-500 rwhp. I think that will be enough power to keep me happy. I'd probably be happy with just a cam swap but why not go big.
I'm also considering a 4.00 crank in the build so I want to make sure these will flow enough in ported form.
I'd like 4-500 rwhp. I think that will be enough power to keep me happy. I'd probably be happy with just a cam swap but why not go big.
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Homer_Simpson (07-19-2022)
01-10-2018, 08:15 AM
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those were the other ones I was looking at. Just didn't know if the extra cost was worth it on these engines when I already have these heads.
01-10-2018, 10:57 AM
#7
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If $$$$ is a concern(and it should be!), just get your heads done and you will be fine.
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Corona (07-19-2022)
01-10-2018, 11:53 AM
#10
Agreed^ Add cubes rather than exotic heads in a NA build you will gain a LOT more. You can build a low buck 414 out of a 6.0L iron block, run whatever heads you want, a cheap shelf cam, and you will blow ANY na 5.3 combo away with ease on any LS head ( Id run 243/799 btw ) or square ports for bigger gains. Both 5.3 with heavy mods or a cube build require fueling/tuning/exh to work well so do it once.
414 with square port heads and your really going to scoot. 9.9x type deal
414 with square port heads and your really going to scoot. 9.9x type deal
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Homer_Simpson (07-19-2022)
01-10-2018, 11:54 AM
#11
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I THINK he's just building this as a street-only daily or fun car, with not much $$$ expenditure. Which is why I think he will be happy with a nice cam and good CNC'd OEM heads. Aftermarket heads would be a bit overboard, IMHO.
01-10-2018, 12:24 PM
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Building the car to cruise around in and occasionally take to shows, drive to the office, etc
I want nice street manners with a manual trans behind it. I want it to be slightly faster than the mustang(I know blasphemy) I had in college that was a full bolt on and tuned car.
Should be pretty easy to outperform it with the newer tech.
01-10-2018, 12:26 PM
#13
If your going to go budget? Stay budget allll the way. Stock 5.3L with stock heads and LS9 cam ( 130 bucks ) puts about 330whp down. Theres plenty of dyno reports with that around. Enough to get you into the 12's if you sort the car out.
If you add 243/799 heads and a decent cam something like the 228r 112 you would run solid 12's
To take a 3400lb car to 11's with a 5.3 is going to cost you, a LOT. So why chase a number? Spend smart money on cubes if staying NA or boost the 5.3 and run 9's all day
cheap/fast/good pick two
If you add 243/799 heads and a decent cam something like the 228r 112 you would run solid 12's
To take a 3400lb car to 11's with a 5.3 is going to cost you, a LOT. So why chase a number? Spend smart money on cubes if staying NA or boost the 5.3 and run 9's all day
cheap/fast/good pick two
01-10-2018, 03:09 PM
#14
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It doesn't need to be all or nothing. A stock 5.3, plus a cam and getting the heads done right, will give him an engine that will do quite a bit.
01-10-2018, 03:15 PM
#15
The OP said he's rebuilding a 5.3 for use as a reliable engine in his 76TA. He didnt state a power goal, he asked about heads. There is no "bad" LS head, notta one aside from the possible castech crack issue which is not even very common so really no bad head performance wise. There is only good, and better.
So without a power goal we are talking money vs performance. I offered two options both RELIABLE as in factory reliable. LS9 cam, blue springs, stock everything else will have 12 second potential in his car with the 5.3. To build a 5.3L to go 11's in that car? Is cost prohibitive, so why waste money? Only fools do that. So its not an all or nothing perspective as in a save or waste perspective. Taking a 6.0L to a relatively easy 11 is possible but a 5.3 that is DD reliable is not so easy. There are some who got lucky and managed opver acheiving performance from 5.3 but thats more lotto luck and not the norm.
So why spend $1000's on heads worth 20-30hp on a basic 5.3 build? Total waste of dough imo.
Of course this is only advice, you can take it or leave it. Its the OP or anyone elses money and time who reads this. Best of it whatever route you choose
So without a power goal we are talking money vs performance. I offered two options both RELIABLE as in factory reliable. LS9 cam, blue springs, stock everything else will have 12 second potential in his car with the 5.3. To build a 5.3L to go 11's in that car? Is cost prohibitive, so why waste money? Only fools do that. So its not an all or nothing perspective as in a save or waste perspective. Taking a 6.0L to a relatively easy 11 is possible but a 5.3 that is DD reliable is not so easy. There are some who got lucky and managed opver acheiving performance from 5.3 but thats more lotto luck and not the norm.
So why spend $1000's on heads worth 20-30hp on a basic 5.3 build? Total waste of dough imo.
Of course this is only advice, you can take it or leave it. Its the OP or anyone elses money and time who reads this. Best of it whatever route you choose
01-10-2018, 03:48 PM
#17
The OP said he's rebuilding a 5.3 for use as a reliable engine in his 76TA. He didnt state a power goal, he asked about heads. There is no "bad" LS head, notta one aside from the possible castech crack issue which is not even very common so really no bad head performance wise. There is only good, and better.
So without a power goal we are talking money vs performance. I offered two options both RELIABLE as in factory reliable. LS9 cam, blue springs, stock everything else will have 12 second potential in his car with the 5.3. To build a 5.3L to go 11's in that car? Is cost prohibitive, so why waste money? Only fools do that. So its not an all or nothing perspective as in a save or waste perspective. Taking a 6.0L to a relatively easy 11 is possible but a 5.3 that is DD reliable is not so easy. There are some who got lucky and managed opver acheiving performance from 5.3 but thats more lotto luck and not the norm.
So why spend $1000's on heads worth 20-30hp on a basic 5.3 build? Total waste of dough imo.
Of course this is only advice, you can take it or leave it. Its the OP or anyone elses money and time who reads this. Best of it whatever route you choose
So without a power goal we are talking money vs performance. I offered two options both RELIABLE as in factory reliable. LS9 cam, blue springs, stock everything else will have 12 second potential in his car with the 5.3. To build a 5.3L to go 11's in that car? Is cost prohibitive, so why waste money? Only fools do that. So its not an all or nothing perspective as in a save or waste perspective. Taking a 6.0L to a relatively easy 11 is possible but a 5.3 that is DD reliable is not so easy. There are some who got lucky and managed opver acheiving performance from 5.3 but thats more lotto luck and not the norm.
So why spend $1000's on heads worth 20-30hp on a basic 5.3 build? Total waste of dough imo.
Of course this is only advice, you can take it or leave it. Its the OP or anyone elses money and time who reads this. Best of it whatever route you choose
01-10-2018, 04:25 PM
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In post #4 the OP clearly stated a horsepower goal of 400-500rwhp. Your advise was sound and I agree with you that the cost/benefit of aftermarket heads are not worth it for a budget DD build. I think he should get his stock castings worked over and pair them with a nice cam and bolt-on's.
Clean up the heads with a little port job, new cam, headers, intake, and a tune. Should run just fine and be enjoyable.
01-10-2018, 09:09 PM
#20
My third post was in defense of my previous posts, as if that is a requirement... I'm only offering out some advice to help inform the guy with cost effective options and encourage good fun.
almost every thread with good advice and someone goes on the attack and why? What in the damn HELL does anyone expect to gain from jumping all up in someone elses OPINION on an internet forum?
Offer your advice, let the people choose for themselves and get on with the pursuit of happiness already. Tearing up another member for their advice isn't doing anyone any good at all.
OP glad you have a plan and are chasing after it
almost every thread with good advice and someone goes on the attack and why? What in the damn HELL does anyone expect to gain from jumping all up in someone elses OPINION on an internet forum?
Offer your advice, let the people choose for themselves and get on with the pursuit of happiness already. Tearing up another member for their advice isn't doing anyone any good at all.
OP glad you have a plan and are chasing after it