Okay; between an LT1 conversion or a Holley Stealth Ram - which would you choose? I found a guy that can supply me with a complete LT1 conversion for my L98 and he'll port it to my existing 58mm throttle body for somewhere between $500 - $700 depending on whether I want it powder coated and some other options.

Alternatively, I can get an HSR, which I understand will cost about $600 total and allow me to use my 58mm throttlebody - but not my strut tower brace and it may also not fit under my hood since I have poly mounts and this car was originally a v-6.

This is for the car that now has a Hi-Flo Edlebrock TPI setup with Edlebrock heads and a mild Crower cam (213/222) making 343 ft/lb of torque at the rear wheels at 3500 and only 243rwhp at 4000.

ALSO - if I'm going to change the TPI (which I am), I'll also get the 190cc AFR heads (190cc over the 195cc as a compromise between port velocity and size) and a bigger cam (222/234). Another fact is that right now, with the 60cc combustion chamber on the Edlebrock heads, I have 10.8:1 compression, which might drop to about 10.5:1 with the slightly larger 64cc combustion chamber on the AFRs.

SO, WITH ALL THE ABOVE INFO - which intake do you guys suggest I get for the best performance?

By the way, anyone know whether I can use my TPI's adjustable fuel pressure regulator on either the LT1 or the HSR?


I'm not interested in a miniram since it's overpriced and I've heard that TPIS products are generally of poor quality.

 

I cant speak on behalf of the LT1 swap but when I was looking at doing the same I had to boil it down to exactly what my goals for the motor are..compared to in reality how I will actually drive it.

I believe the LT1 has more potential to be opened up for a very high revving motor if you build the rest of the block to support it,but even less bottom end torque off the line.Ask yourself simple/stupid question..will I spin this motor upto 7000+rpm..and if so..will if be often.Odds are probably not.I also asked myself do I want to worry about the converted Lt1 having potential leaks with head gaskets or distributor mount issues others had when they were first being done..I choose a more sure fitted route for me.The HSR compared to LT1 are very close...HSR can be ported to a degree still and pull to 7000 if you choose but its not a necessity from what I understand your goal of this build is.Both will require you to move your fuel lines,the LT1 gives you the option to use an egr if you need it

To be honest about the stb..I noticed no real change having it on or off my car and taking turns hard at the same speeds.Maybe due to other suspension mods that were a better upgraded yeilded it a very small performance step up(bushings,sway bars,sfc,panhard bar,steering brace) other than the astethics os the reason I want to custom make something around my HSR.

The fpr will not work on the HSR fuel rails..Im not sure if they are compatible with the LT1 either..I dont think they were.

I really suggest you search the archives about both intakes..think about your goals for this motor... and if you ever plan on upgrading from here because it never just ends after one build lol

 

The TPI fuel pressure regulator will not work on LT1 fuel rails.

The LT1 manifold is excellent for opening up your upper RPMs. As far as performance is concerned, I LOVED the LT1 intake swap on my L98.

What I absolutely regretted was the remote thermostat configuration. Too many extra fittings and hoses in the engine bay. The coolant ports were an issue for my intake and the manifold has to be TIG welded to resolve the issues.



I later purchased a TPIS Mini Ram to resolve the issues of the LT1 intake conversion cooling system...and then ditched the distributor for coil per cylinder ignition.

But the engine pulled and pulled past 6,000rpm with the LT1 intake. Good times!