I recently popped a whole in my #1 piston on my 408 w/nitrous and we are in the process of rebuilding it. I had planned on going a different route eventually when this motor let go, but it happenned a little sooner than I expected We are going to rebuild it with an extra 10 thousands over bore so it will be 4.040" bore and 4" stroke. We decided to go ahead and build it for forced induction at this time and add a power adder next year. The compression ratio will be about 9.25 to 1. I was leaning toward a procharger setup and figured I would go ahead and put a cam suitable for it while we were rebuilding anyway. During my research I found that the Iron block does not have the bolt holes for the procharger. The motor is at the builders shop now so I don't know for sure, but I believe it already has the one hole tapped.

I'm curious to hear from people with procharged Iron blocks to see how many miles you've put on the setup, how much power you're making, and if you've had any issues with running only 2 bolts on the block.

Even tho. we are just building the motor this year I would like to have a firm Idea of what my long term setup is going to be so I can get the proper cam now. I was dead set on a f1-a until I found out about this problem. I'm looking to make about 700 rwhp through an auto with as low of boost as I can and I don't want anything "maxed out".

 

Making over 700 with mine and I have had it that way for about 7000 miles which includes several passes at the track! You'll be fine!

 

Been there..........Done that!! Ha..

http://www.ls1gto.com/forums/showthread.php?t=88194

 

tap the bolt hole out, its around .700-.800 deep for drilling then tap out to the m10 thread.

You will need to tap it as the f1 blower will need a really tight belt not to slip. Or get a sdce bracket. A d1sc will be getting close to maxxed on 700ish hp (mustand dyno).

As for a cam, whats the final goal of the car? Street? Strip?

Give us a ring if you want to go through the run down of what you have and what your wanting out of the setup, can help you get into a good cam that will make power where you need it.

 

Outstanding write up!!! So are you still just using 2 bolt holes then?

 

So you are saying I definately need to tap the 3rd hole in the block for the f1 blower? That's the one I don't really want to fool with. The car is for street use, but I do want it to perform at the track. I was thinking I could run a larger crank pulley and that would help with belt slip and I wanted the f1 so I wouldn't have to spin it to hard to make the 700 rwhp. I don't want to drive a maxed out d1 on the street in the summer. Anybody make a custom mount to tie the blower to something else?

 

Its really easy to do and very worth it, 3 holes is alot better then 2 obviously.
I would personally tap the hole for a p1 , do it right the first time and you dont have to worry about it.

It is a simple process, just bolt the bracket on, line it up and mark the placement. Drill .700 and then tap out for it, all done with alot more holding power, nothing to sweat.

700hp is going to be a d1sc at around 15psi or so on a 370-400in motor depending on heads and cam.

A f1a will be a tad diffrent in the power band, it is ALOT noiser then a d1sc so if its street duty that may be an issue for some people.

 

The GTO alternator bracket is only using the two on front of the block (upper and lower) there is another alternator bracket on the bottom of the alternator. I am not using the center attach point on the alternator bracket.

The procharger bracket lower attach point, replaces the Alternator bracket upper bolt with a threaded rod and nut. Drilling and tapping the block as shown is to pick up this attach point.

 

Like Jake has mentioned, go ahead and tap the block out, as it is very easy to do, and the block material is there to do so. My 408 with an F-1A can be seen here. http://www.exoticperformanceplus.com...Car.php?car=12
Bob

 

i have more than 25,000 miles on my 2 hole iron block and F1-R blower without any issues.
i would definatly go with the SDCE kit since it adds a support brace to the bracket which makes it a lot more rigid.

 

I put 2 years & lots of racing on my D1 with 2 holes with no issues. I now have an F1 (only ~100 miles so far) with 2 holes + the brace ATI gives you that runs from the head unit at an angle to an oil pan bolt. When you add in the rear alternator bracket bolt it's pretty solid....

 

Your car is quick I seen some vids. But I would tap it just to be safe