347 with Gt-40X heads
Thread Starter
6th Gear Member
Joined: Jan 2007
Posts: 5,464
From: Milford, Delaware
347 with Gt-40X heads
Is it worth putting a set of mild ported &shaved .25 gt-40X heads on a 347? I would rather have AFR's but I already have these. I have a spare block and was gonna build me a 347 short block over the winter.
2nd Gear Member
Joined: Oct 2005
Posts: 202
From: Connecticut
RE: 347 with Gt-40X heads
If your going to do it, go to a dyno first and then after. Those heads can flow enough if you massage them right. Im sure that spare block is calling out to you, but is it a roller block? I have a 347 and I built it as far as those blocks can go. The stock small block can only handle around 400hp. Plus, to get that kinda power out of it, I spent around $10,000 in parts. The 347 stroker puts weares out quicker too. If your going to spend alot of money on a motor you might want to look into a big block. You can get more power at the same price if not cheaper. Also, if you plan on racing in a catagory, look to see what catagory fits the motor you are thinking about building and build it within those requirements.
6th Gear Member
Joined: Feb 2005
Posts: 13,396
From: KY
RE: 347 with Gt-40X heads
ORIGINAL: 97targa
I have a GT-40 FRRP Tubular upper/lowerintake set-up for sale. Not sure what you've got, but it will def. give good gains up top!
I have a GT-40 FRRP Tubular upper/lowerintake set-up for sale. Not sure what you've got, but it will def. give good gains up top!
and we have a forsale section
5th Gear Member
Joined: Sep 2004
Posts: 3,145
From:
RE: 347 with Gt-40X heads
ORIGINAL: turt
If your going to do it, go to a dyno first and then after. Those heads can flow enough if you massage them right. Im sure that spare block is calling out to you, but is it a roller block? I have a 347 and I built it as far as those blocks can go. The stock small block can only handle around 400hp. Plus, to get that kinda power out of it, I spent around $10,000 in parts. The 347 stroker puts weares out quicker too. If your going to spend alot of money on a motor you might want to look into a big block. You can get more power at the same price if not cheaper. Also, if you plan on racing in a catagory, look to see what catagory fits the motor you are thinking about building and build it within those requirements.
If your going to do it, go to a dyno first and then after. Those heads can flow enough if you massage them right. Im sure that spare block is calling out to you, but is it a roller block? I have a 347 and I built it as far as those blocks can go. The stock small block can only handle around 400hp. Plus, to get that kinda power out of it, I spent around $10,000 in parts. The 347 stroker puts weares out quicker too. If your going to spend alot of money on a motor you might want to look into a big block. You can get more power at the same price if not cheaper. Also, if you plan on racing in a catagory, look to see what catagory fits the motor you are thinking about building and build it within those requirements.
Thread Starter
6th Gear Member
Joined: Jan 2007
Posts: 5,464
From: Milford, Delaware
RE: 347 with Gt-40X heads
The block is a roller, I'm not trying to make crazy horse power but want something pretty quick. How much horse could the 347 put out with the ported gt-40X heads and a mild cam?
