98redstang

+1 for the ported pi swap. My tune sucked thats the only reason im at the rwhp mark im at. When they tuned my car the rear brakes were dragging. The jacka$$ that built the motor didnt put the pilot bearing in either so once you got up to around 4500rpms it would shake like crazy and you wouldnt be able to go any higher(it also cost me 1000 bucks for a new tranny which he ended up paying for). And he didnt even touch my timing. So with a good 93 tune people were saying i should be around 315rwhp with my mods. Just a thought... But i also see what teej is saying so i would say whatever would be the cheapest route if your on a budget op.

RyanK

Well Yes I am on a budget, But from all my reading everyone said swapping the pi heads is a waste that the intake and cams are what is holding me back, so Im going with either 2.5 or 3 mhs cams, the edlebrock intake full bolt ons head p&p and mainly I want a thread for people that are thinking about going npi can see what the numbers look like because not alot of people go non pi? And worst it doesnt create very much power ill take the heads off buy the pi heads P&P call it done.


Can i use mhs pi cams? or should I go with there npi cams? I cant wait to start ordering stuff just need to get my list down to exactly what I want im excited(:

teej281

You can use PI cams if im not mistaken, its just the intake centerline will be less than what you could run due to the PI heads having more PTV issues than the NPI's. So you could go with some reasonable PI cams and then if you switch to PI heads, get your pistons notched or your valves will be getting to know your pistons more than they should...and we'll just say that the relationship will be very abusive.

RyanK

so could i only run sock pi cams or some from mhs ?

98redstang

you can run the mhs cams. Hes saying hes pretty sure you can run pi style cams in general wether it be stock or custom. Just when/or if you switch to a pi head than you need to notch your pistons or valves cause you'll run into ptv clearance issues. Your fine with the npi heads i believe cause you have more ptv clearance.

nickmckinney

You need more cam and compression. Get a set of 4V -3cc replacement pistons.

Here is a video of a NPI car with MHS Stage 3.5 cams and Edelbrock intake short shifting at only 6000 because he hasn't retuned it for the new cams yet:

NPI happiness

RyanK

so how much cam should i go with a 3.5 or a 4? and where would i find those pistons does it matter if there used or new?

nickmckinney

That guy is using a stock used Mark VIII bottom end with upgraded rods. I have built many NA motors reusing the stock 4V pistons. All depends on what kind of shape they are in, they usually hold up really good in the Mark cars.

nickmckinney

cam choice depends on RPM range, with the Edelbrock and Stage 3.5 cams you should be shifting around 7000 or so.

RyanK

would cobra pistons work? or does it need to be the mark?