347 for my 90 GT Vert?

tjm73

Founding Member
Aug 3, 2000
2,418
1
48
Rush, NY
Kickin around an idea to build a 347 for my 1990 GT 'Vert. I've decided I want to build it for torque since it's 99% a street car and convertibles are heavy. So torque is where it's at for my car. I'm looking at the following combo.

347 Stroker kit with 5.315 rods so the oil controll ring and piston pin don't intersect.
Main girdle w/ windage tray
Trickflow TW engine kit from Summit Racing with the middle TF cam in place of the small TF cam.
10:1 compression
70mm TB/EGR

Currently I have....
Crane Ignition
Adjustable Fuel PSI Reg
73mm C&L MAF
FRPP 24 lb injectors
MAC 1 5/8" Headers
MAC 2 1/2" Cat H-Pipe
MAC 2 1/2" Cat-back

...on my car. Am I missing anything vital?
 
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tjm73 said:
Kickin around an idea to build a 347 for my 1990 GT 'Vert. I've decided I want to build it for torque since it's 99% a street car and convertibles are heavy. So torque is where it's at for my car. I'm looking at the following combo.

347 Stroker kit with 5.315 rods so the oil controll ring and piston pin don't intersect.
Main girdle w/ windage tray
Trickflow TW engine kit from Summit Racing with the middle TF cam in place of the small TF cam.
10:1 compression
70mm TB/EGR

Currently I have....
Crane Ignition
Adjustable Fuel PSI Reg
73mm C&L MAF
FRPP 24 lb injectors
MAC 1 5/8" Headers
MAC 2 1/2" Cat H-Pipe
MAC 2 1/2" Cat-back

...on my car. Am I missing anything vital?

First of all what block are you planning on running? I hope it is not the stock one. If I were building it i would go with a bigger maf/throttlebody. 75mm throttlebody/80mm maf. Also you are going to have to get some sort of tuning device. I don't see gears in your sig? Do you have any?
 
mackey said:
First of all what block are you planning on running? I hope it is not the stock one. If I were building it i would go with a bigger maf/throttlebody. 75mm throttlebody/80mm maf. Also you are going to have to get some sort of tuning device. I don't see gears in your sig? Do you have any?

Yes stock block. It won't see more than 6000 rpm and it'll be getting a precision balence. Stock block will take it. I'm estimating a max of 300-350 rwhp (about 400-425hp @ crank max). Well within the cababilities of the stock block.

My car is a 5 speed, has 3.73 gears
 
If it's a street cruiser with a little bruising then torque is what you want to shoot for. Your stock block should take it, plenty of people running the stock block making even more power without problems. Building the engine for a broad powerband in your case is what I would do. I think the setup your planning will really work well.
 
All I'd add is that if you're gonna spend that kind of money on the motor (and it will be nice), get Buddy or Ed to spec the cam for you. Tell them what you want in terms of peaks and the rpm range you're after. The TW cams were designed for 302 cubes and will behave entirely differently in a 347. Spend another $150 and get a cam that's actually designed for your desires and displacement.
 
i agree with Yount on this one. a custom cam is the way to go. If your gonna spend that much money on a 347, you might as well get something that is really going to kick a$$ for you. the motor that your planning will make the power that you want. i also do agree that a 75mm t-body and 80mm Pro-m is the way to go. also, a powerpipe from Anderson Ford will help too.
 
I have a BBK inlet pipe. Don't know if it'll attach to a 75mm throttle body inlet. Would rather not replace it if I don't need to. And I still have the stock throttle body. The 73mm C&L MAF is (according to C&L) good to around 600 hp or so. So I'm having trouble accepting it woun't be big enough. :shrug:

A custom cam kinda sounds like a good idea now that you mention it. Hadn't really thought about that. :nice: