Finally decided on a combo need opinions

[Bigstang1]

I have laid down a combo that i want to build in the spring and i need some opinions here it is:

gt40p heads: with .600 springs and 1.94/1.5? valves...i am going to mill them .040 to get around 10:1 compression(unless i can find some cheap alum.)

Typhoon or Trick flow street heat intake

B303 or trick flow stage 1 or 2 cams

I will also be freshening up the bottom end with new rings and main and rod and cam bearings. This combo will be behind a freshly rebuilt t5 and 3.73 gears. I am adding a 355 lph fuel pump and regulator if i need it. will i need bigger injectors? As u have noticed there are a few options in my combo what do you guys think?

 

[N8Miller]

I think that you will have a nice street set up there. those are nice heads for around town and on a budget and making some decent power.
as for the cam, i would stay with a stage 1 TFS. that will work better with your heads i think. however, i would go with a typhoon intake. that is the RPM version if i remember correctly? i love the RPM intakes. i think that will work good becasue it will give you power to like 5700 or whatever it is Vs. the stock 5200 rpms.
ps, if your hurting for $, go to the classified section and get some used pullies and get a short belt to bypass your smog set up.

 

[Rick 91GT]

I think with 175,000 miles on it you may find the bores are tapered and you will need to bore it .030 and put pistons in...some do some don't.

Sometimes when you start milling the heads .040 you will also need to have the intake milled to match.

 

[mike keirstead]

I think with 175,000 miles on it you may find the bores are tapered and you will need to bore it .030 and put pistons in...some do some don't.

Sometimes when you start milling the heads .040 you will also need to have the intake milled to match.

I agree with RICK. The cylinder walls should be checked. There is no sense in building a nice combo that will rev cleanly past 5500 and then have to rip it all back apart again to fix something. My block had 160,000 on it and it needed .040 to get the bores cleaned up. If there is a deep ridge where the piston reaches TDC it will likely benefit from a bore job.

A friend of mine milled his Gt-40Ps .045 and he had to have the intake done as well. Try to find out what you can safely mill the heads and not have to do the want to keep the cost down. Stock compression on a 5.0 with gt-40Ps is around 9.2:1. Also if you increase your bore it will bring you a little closer to your desired 10:1. Not much but it will. It all really depends on how much cash you want to spend.

Also, I didn't think that 1.94s would fit in a gt-40 P head. I thought 1.90 was the max. Maybe I am wrong.

The rest of your combo sounds good. I would get the TFS street or the Edelbrock performer. The typhoon and the RPMth have shorter runners and are meant for better flowing heads. They would really be overkill on GT-40 Ps without portwork.The TFS street would be a good match. Good luck with your lower end.

Mike

 

[Bigstang1]

Well if i have to do the pistons im gonna build a cast 347. It will be more $$$ because i will have to get much better heads which i will most likley have to buy used. If i go with a 347 what are some good heads...im guessing aluminum is the way to go. I know i cant afford any afrs so... Thanks i know this changes the whole thread but i hope i can get some answers caquse this is my first performance engine build. I got 1 stock rebuild under my belt just lat week so im learning lol thanks

 

[Nottoofast50]

What is your budget like? Reason I ask is after all that work and buying the gt40p heads your going to be close to if not at the same price as some aluminum heads that will be even better. I just bought some gt40ps myself and was debating on whether or not to get them ported and milled but after buying the heads(close to $475 after shipping) and getting the work done 4-500 it would be almost 1k. I chose to just stick with the box stock gt40ps... just something to think about.

 

[Bigstang1]

My budget is like as cheap as i can do it but still doing it right. Im 17 and in highschool but i think i can get a lend of money to do the car and pay them back later.