Head selection assistance
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From: Lantana TX
Head selection assistance
Hey all,
Hope everyone is doing well! I am about to go out and purchase a new set up heads for the Vette and looking to you folks to help me pick the right set since I have no idea what to get. I am also going to swap out the cam in the near future, maybe a month. I am looking at a mildly aggressive cam 490 lift range and do not know if this will affect the head selection. I have read many of the posts here, but cannot come to a conclusion on the name or size of head. How do you figure this out? With the help of a nearby friend, we will swap them out ourselves so the goal is to spend under $1200 for a set. Is there such thing as to big?? My Vette spec’s are below.
Hope everyone is doing well! I am about to go out and purchase a new set up heads for the Vette and looking to you folks to help me pick the right set since I have no idea what to get. I am also going to swap out the cam in the near future, maybe a month. I am looking at a mildly aggressive cam 490 lift range and do not know if this will affect the head selection. I have read many of the posts here, but cannot come to a conclusion on the name or size of head. How do you figure this out? With the help of a nearby friend, we will swap them out ourselves so the goal is to spend under $1200 for a set. Is there such thing as to big?? My Vette spec’s are below.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
The problem with my L-82 355 ci Vette was not enough head flow or compression. So I installed 64 cc heads to get @ 10.7 compression. With bigger heads and cams to spin it to over 7000 rpm every day of the week.
I also had a TH350 and 3.55 gears. In one version of the motor that lasted for nearly 50,000 miles was a consistant 12.70 bracket car on slicks.
The real problem is 355 ci. You will be dollars ahead to put a blower on it or just get rid of it and get over 400 cubic inches. skip the wimpy 383. Your going "NOT" to be happy
Unless you have 600 hp and over 500 foot pound of TQ
My advice is to not beat a dead horse. It's either a big blower sticking out the hood or as many cubic inches as you can
I also had a TH350 and 3.55 gears. In one version of the motor that lasted for nearly 50,000 miles was a consistant 12.70 bracket car on slicks.
The real problem is 355 ci. You will be dollars ahead to put a blower on it or just get rid of it and get over 400 cubic inches. skip the wimpy 383. Your going "NOT" to be happy
Unless you have 600 hp and over 500 foot pound of TQMy advice is to not beat a dead horse. It's either a big blower sticking out the hood or as many cubic inches as you can
Last edited by gkull; Feb 13, 2006 at 06:02 PM.
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From: Lantana TX
Originally Posted by gkull
The problem with my L-82 355 ci Vette was not enough head flow or compression. So I installed 64 cc heads to get @ 10.7 compression. With bigger heads and cams to spin it to over 7000 rpm every day of the week.
I also had a TH350 and 3.55 gears. In one version of the motor that lasted for nearly 50,000 miles was a consistant 12.70 bracket car on slicks.
The real problem is 355 ci. You will be dollars ahead to put a blower on it or just get rid of it and get over 400 cubic inches. skip the wimpy 383. Your going to be happy Unless you have 600 hp and over 500 foot pound of TQ
My advice is to not beat a dead horse. It's either a big blower sticking out the hood or as many cubic inches as you can
I also had a TH350 and 3.55 gears. In one version of the motor that lasted for nearly 50,000 miles was a consistant 12.70 bracket car on slicks.
The real problem is 355 ci. You will be dollars ahead to put a blower on it or just get rid of it and get over 400 cubic inches. skip the wimpy 383. Your going to be happy
Unless you have 600 hp and over 500 foot pound of TQMy advice is to not beat a dead horse. It's either a big blower sticking out the hood or as many cubic inches as you can
and know how to perform an engine swap. This being said most of the work is being done by a local shop. My end goal is to just have a vette that I can readily stomp on and one that produces around 400-425 RWH. This should put me around 500 hp gross. Blower is down the road and will most likely be the case, but I must address the heads (stock=pieces of junk) and cam (whimpy) first.Present spec's that I forgot to included
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From: Orange massachusettes
skip the 383?? Do you recomend a small block 400 or are you saying go to big block? I was considering a 383 stroker, looked to be able to build one for less than $3500 . As for heads I have heard good things about AFR's, but also not sure what size (180's 190's??) for strong street performance.
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From: Lantana TX
Originally Posted by 72 LT1
skip the 383?? Do you recomend a small block 400 or are you saying go to big block? I was considering a 383 stroker, looked to be able to build one for less than $3500 . As for heads I have heard good things about AFR's, but also not sure what size (180's 190's??) for strong street performance.
I am origionally from RI an can feel your pain.Sorry couldn't resist that one
Safety Car
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From: San Antonio TX
I almost barfed when I read Gordon's response, but then reading your followup for what you want...I'd have to agree with Gordon. Best way to get that kind of power with a streetable engine is massive cubic inches or boost. 425RWHP is a lot harder than you think especially if you're working under 400ci. You'll need a lot of rpm with a small engine to make that kind of power. If you don't slim down your hp expectations, you're going to go through an awful lot of cash. Around $12,000 ought to get you there reliably.
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From: Lantana TX
Originally Posted by gerry72
I almost barfed when I read Gordon's response, but then reading your followup for what you want...I'd have to agree with Gordon. Best way to get that kind of power with a streetable engine is massive cubic inches or boost. 425RWHP is a lot harder than you think especially if you're working under 400ci. You'll need a lot of rpm with a small engine to make that kind of power. If you don't slim down your hp expectations, you're going to go through an awful lot of cash. Around $12,000 ought to get you there reliably.
I forgot to say that getting 425 RWH includes 125 shot of NOS (sorry). I am at 235 RWH with out NOS and 335RWH with the NOS. All I am looking for is an additional 75 RWH with out the NOS. This will put me at 320 RWH and another 110 on the NOS. Total RWH would then be 420.
Is this too much to ask for?
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From: Lantana TX
Originally Posted by 72 LT1
gerry72 I have seen stroker 383 crate engines rated over 500hp and close to 500ft torque for under $8000. I'm not sure how hp #s at crank convert to hp #s at rear wheels.
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Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Change cam and heads and you will get what you are looking for. AFR heads and XE274 cam would work well 
I don't put alot of faith in claims about big HP ( especially the ones with 195cc heads ) unless they actually put the motor on a dyno.
THat is what I did and if you look in my my sig you will see what it takes to hit the magic 500/500. It will cost you about 8-10 grand.
I don't put alot of faith in claims about big HP ( especially the ones with 195cc heads ) unless they actually put the motor on a dyno.
THat is what I did and if you look in my my sig you will see what it takes to hit the magic 500/500. It will cost you about 8-10 grand.
Last edited by MotorHead; Feb 13, 2006 at 06:47 PM.
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From: Lantana TX
Originally Posted by MotorHead
Change cam and heads and you will get what you are looking for. AFR heads and XE274 cam would work well
I don't put alot of faith in claims about big HP ( especially the ones with 195cc heads ) unless they actually put the motor on a dyno.
THat is what I did and if you look in my my sig you will see what it takes to hit the magic 500/500. It will cost you about 8-10 grand.
I don't put alot of faith in claims about big HP ( especially the ones with 195cc heads ) unless they actually put the motor on a dyno.
THat is what I did and if you look in my my sig you will see what it takes to hit the magic 500/500. It will cost you about 8-10 grand.
Can you go to big on heads??
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I had a hot rod 383 with Dart 227cc heads and solid roller cam. IMO there is no reason to build these smaller ci motors. Because for the same cost your can build 396 ci out of 350 blocks or just jump up to 400+ ci.
I was initially impressed with the power of my 383 over my previous hot rodded 355 ci motors. That wore off about the third set of my rear 315/35 tires. I tried some larger SR cams and all it did is force me to run the motor to 7500 rpm.
Now that I switched to 427 small block I could never recommend small motors to anyone. Unless they use forced induction.
I was initially impressed with the power of my 383 over my previous hot rodded 355 ci motors. That wore off about the third set of my rear 315/35 tires. I tried some larger SR cams and all it did is force me to run the motor to 7500 rpm.
Now that I switched to 427 small block I could never recommend small motors to anyone. Unless they use forced induction.
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
In my opinion you can't go too big on heads as long as you match everything up. BIgger heads require higher compression ratio, bigger cam, bigger carb etc.
For your 355ci and XE274 cam I would recommend the 195cc AFR's. They only way to get 425RWHP though would be to add the 125 shot
For your 355ci and XE274 cam I would recommend the 195cc AFR's. They only way to get 425RWHP though would be to add the 125 shot
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From: Southeast
I recommend the Trick Flow 195cc runner 23 Degree Heads. I just put a set of 64cc's on mine. Runs very strong and a very good head. I've got around 10:1 CR with .020 flat-tops. Here's a video posted in General of just revving it up and letting it idle. Video If you scroll on down in the thread, you'll see what my full set-up is.
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From: Lantana TX
Originally Posted by MotorHead
In my opinion you can't go too big on heads as long as you match everything up. BIgger heads require higher compression ratio, bigger cam, bigger carb etc.
For your 355ci and XE274 cam I would recommend the 195cc AFR's. They only way to get 425RWHP though would be to add the 125 shot
For your 355ci and XE274 cam I would recommend the 195cc AFR's. They only way to get 425RWHP though would be to add the 125 shot
Sorry for so many questions but I want to do it right the first time around. Should I get the 68cc or 74cc version? What is the difference?
Looking at pricing...Are they realy $1300 per head or for the set?
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
The pair is $1300, still fairly expensive but they are good heads, the only 195cc head out of the box that will get close to 500HP with a 383 short block.
The head chamber is determined by what pistons you have, but I would think you would be looking at the 68cc heads to raise your compression ratio a bit
The head chamber is determined by what pistons you have, but I would think you would be looking at the 68cc heads to raise your compression ratio a bit
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From: Lantana TX
Originally Posted by MotorHead
The pair is $1300, still fairly expensive but they are good heads, the only 195cc head out of the box that will get close to 500HP with a 383 short block.
The head chamber is determined by what pistons you have, but I would think you would be looking at the 68cc heads to raise your compression ratio a bit
The head chamber is determined by what pistons you have, but I would think you would be looking at the 68cc heads to raise your compression ratio a bit
Thanks, I have no problem spending $1300 budgeting $3000 for the total build...what if I do not know what kind of pistons I have? I absolutly want to raise my compression stock is 8.5:1. Do you know what this might bring it to?
Again I realy appreciate the assistance you have given me. Maybe someday I can be as helpfull to the forum.
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Joined: May 2005
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From: Jennings LA
Originally Posted by 72 LT1
skip the 383?? Do you recomend a small block 400 or are you saying go to big block? I was considering a 383 stroker, looked to be able to build one for less than $3500 . As for heads I have heard good things about AFR's, but also not sure what size (180's 190's??) for strong street performance.
190's
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From: Marietta ga
Originally Posted by 76 sting
Thanks, I have no problem spending $1300 budgeting $3000 for the total build...what if I do not know what kind of pistons I have? I absolutly want to raise my compression stock is 8.5:1. Do you know what this might bring it to?
Again I realy appreciate the assistance you have given me. Maybe someday I can be as helpfull to the forum.
Again I realy appreciate the assistance you have given me. Maybe someday I can be as helpfull to the forum.
3k is not much to spend if you are changing pistons. By the time you pull your block, which will most likely need to be punched out, get new hardware, pay the machine shop, buy heads, buy a cam, lifters....etc you will spend no less than $3500 if you build the motor your self.
If replacing your pistons is not an option, I would pick another cam that will work well with lower compression.