[nicko72gto]

could you please help me, i am building a 72 gto 400 4 speed its my first car seeings how im 15 years old i would like some help on some cheap engine upgrades i can do. the engine is a pontiac 400 with 69 judge ram air heads and cam, performer rpm intake with a 750 edelbrok carb, 2 inch flowtech headers borg warner super t-10 4 speed gm short throw shifter, through 3.73 gears posi trac rear end, im getting my rea ralle 2's extended for a bigger rear tire. can you please help me by telling me what i can do to make my engine faster with under 800 dollars i have also set up functional ram air for it any suggestions thank you
nick markey

[nicko72gto]

could you please help me, i am building a 72 gto 400 4 speed its my first car seeings how im 15 years old i would like some help on some cheap engine upgrades i can do. the engine is a pontiac 400 with 69 judge ram air heads and cam, performer rpm intake with a 750 edelbrok carb, 2 inch flowtech headers borg warner super t-10 4 speed gm short throw shifter, through 3.73 gears posi trac rear end, im getting my rea ralle 2's extended for a bigger rear tire. can you please help me by telling me what i can do to make my engine faster with under 800 dollars i have also set up functional ram air for it any suggestions thank you
nick markey

[jwcfbd]

by the looks of it you have done just about everything you can on a budget. Just make sure you get a good breathing exhaust system. I would go with either a PYPES or Flowmaster system.

[nicko72gto]

yea i was going with flow master what size should i do? i was thinking 2 1/2 inch. i also heard that if you put a 455 crank on a 400 it helps boost torque is that true?

[nicko72gto]

the engine also has roller rockers i forgot to add that

[SupergasDil]

Nick,
You would be happy with the performance and the sound of the 2 1/2".

Yes there is a 455 crank that's available to fit the 400 block. I believe you would need to bore your 400 .030 which is a standard 455 piston size. You would need a new crank, pistons, rings, and probably bearings. Might as well throw in a new timing chain while you're at it. But with machining and parts you're looking at close to $2,000.

It looks like you've already got an awesome set up. Especially with the 722 heads. If I was you, I'd save my money for a 455 or 474 build up somewhere down the road. Once you have the cubes, there's no going back!

[nicko72gto]

would the combo i have perform very well in the quarter?

[johnta1]

I'm assuming the Ram Air Judge heads are the Ram Air III (48) heads.
Get them ported for more flow and you will pick up more HP.

I would say your combo right now should be in the mid 13's with traction.

[nicko72gto]

thanks alot for the help, does anyone know what size of rear tire i can fit? and is a 750 edelbrock too much?

[SupergasDil]

I had an L6015 on my 70, whatever that is equivalent to.

[bmpmdf]

A 275/60-15 should fit with no issues. On the mufflers, go with Megnaflows. They will help your power and not have that annoying drone going down the road like hp robbing flowmasters. BTW, On a mid 600's hp engine, in a 3" form, the megnaflows made nearly 30 more hp than flowmasters chamber series and the megnaflows were quiter ( not quite though!!!) than the flowmasters. We spent the day dyno'ing nothing but mufflers after the timing and jetting. Interesting is this was Megnaflows street 3" mufflers and they still made nearly the same hp more than the 2 chamber flowmasters as the 3 chamber ones.

[lethal-428-lemans]

bmpmdf is right on with the 275/60r15 tires they fit perfect on my 71' they are right around 28 inches tall. With your gears I would not want to go much shorter on tire hight.

Something else I would look into is a good ignition system like MSD or Mallory and good ignition wires.

I like Mallory uni-lite distributer and Taylor race wires.

[nicko72gto]

how wide of a tire is that?

[nicko72gto]

SupergasDil http://www.angelfire.com/fl4/pontiac...sspecials.html so will that fit right in my motor, i just tore it down tonight and found out its been 0.030 over and i think were doing it 0.040 over

[lethal-428-lemans]

Nick,
The tread patch is 9" the tire is 28" tall
I have mine mounted on ralley II's.
Here is an old pic to give you an idea on fit. I'll get you a better one once the rain stops.
Patrick.

[Motor Daddy]

Not sure if I should suggest this to you being 15 and all, with lack of experience behind the wheel, but here it is anyway (hopefully you are a smart driver).

That $800 dollars would buy you an Edelbrock RPM nitrous system (100-250hp), and a good 140GPH pump to feed it with a few extras. I have a fairly similar combo to yours with the Nitrous system. It is the best bang for the $$. It will be very addictive very quickly I must warn. You will totally destroy a stock Z06, I can tell you that!

[charles vance]

Markey, why are you willing to spend hard earn money on those Choke Masters, they’ll only degrade your performance. “There for the Chevy crowd�

[Doug Christie]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by bmpmdf:
A 275/60-15 should fit with no issues. On the mufflers, go with Megnaflows. They will help your power and not have that annoying drone going down the road like hp robbing flowmasters. BTW, On a mid 600's hp engine, in a 3" form, the megnaflows made nearly 30 more hp than flowmasters chamber series and the megnaflows were quiter ( not quite though!!!) than the flowmasters. We spent the day dyno'ing nothing but mufflers after the timing and jetting. Interesting is this was Megnaflows street 3" mufflers and they still made nearly the same hp more than the 2 chamber flowmasters as the 3 chamber ones. </div></BLOCKQUOTE>

bmpmdf, so your saying that you can gain 3-5% HP by just going to the Magnaflo's over the Flomaster's? Wish I'd known that 2 years ago! Their website say's 10% gain, but that must be over the stock exhaust.

[buwalda]

I have used two sets of Magnaflow mufflers & they are great. Nice sound, with authority, but not overly noisy & without the dreaded drone. I did not do any dyno testing, but I could feel an improvement over two other brands that I tried.