how does a converted LT1 intake with Dart's compare to stock LT1 motor???

Will a converted LT1 intake on a 97 standard 350 roller block with ported Dart iron eagle's, a HOT 4 cam and 1.6's, outperform an LT1 motor with stock heads and HOT cam???? also I have 11.2 to one compression (had heads milled to 58cc).

That's quite a bit of compression for iron heads. You might want to try to back it down a bit. The LT1 has the benefit of aluminum heads which disipate heat much better and weigh like 30 lbs less per head. I think your better flowing heads will produce more HP than the stock LT1's but they will probably cause detonation if you aren't careful.

How could I go about dropping the compression without going into the motor?? I was told if I had an MSD ignition and a bigger than stock cam, than it would lower the chances of detination. I only run 93 octane and mix it with 110 occasionally. Never have had a problem with spark knock or anything.

Well, if you haven't had a problem with detonation, then I wouldn't worry about dropping the compression. I was just pointing out that with that kind of compression the possibility was there.

Just out of curiosity, what kind of piston to valve clearance do you have with those heads? I'm assuming you started with a set of 64 cc iron eagles and then had them milled to 58 cc.

Nope....Never had any problems with detination yet. Yes, those heads were originally 64cc's and I had them milled to 58cc's. I cant remember the exact valve to piston clearance. We got a piece of play doh and pressed it flat to the piston, then turned motor over with a ratchet and pulled the head back off and checked the indentions on the play doh and had maybe 1/4 to 3/8's of an inch between the valve and piston. Just wondering....How would you think that my setup would compare to an LT1 with the same mods??? Only difference being the Dart heads??? I'm thinking of buying an LT1 and building it up, and I have an L98 block with the vette aluminum heads and it needs to be rebuilt. Plus I have acquired a set of Edelbrock performer rpm heads, and I dont know which way to go??? I want to go with the cc306 cam with the next setup, either way.....What would you recommend???

I would pass on the LT1. Honestly, LT1's in 3rd gen cars have been done to death. Plus you have to worry about the Opti spark which is a pain in the butt, believe me. Not to mention you will have to get a new computer/wiring harness and I can't remember what else I was going to say that you will need.

If it were me, I would take the L98 block and punch it out to a 383 and put the Performer RPM heads on it with the CC306 and the LT1 intake you have. I would probably do the 4 bolt main conversion just for insurance. You've already got most of what's needed and you can get a really good rotating assembly for very little. The Eagle balanced 383 kit that I'm using has forged pistons, 6.0 inch H beam rods, a forged crank and a flywheel for $1700 dollars (I think I payed a little extra for the 1400 Hp rod bolts). If you don't feel like doing the 383, a 350 setup would still work well (but those magic 33 extra cubic inches are nice).

As far as how your current setup compares with an LT1, it should run about the same time as a LT1 that's set up with unported stock heads and the same cam/rr's/everything else (12.70's or so, maybe a bit faster with traction). Yes, your Darts give you more compression and better flow, but they also add probably close to 60 lbs of weight to the car
(:bow: Aluminum:bow: ). I'm just guessing, if you want to find out how it does, take it to a local track when they open up in the spring and see how it does.

Thanks for the input SCharged!!! I'm kinda leaning toward that L98 block for building, too. About how much will it cost for me to have the block machined for a 383?? How did it compare to your previous motor??? If I did go with the LT1, I would just have John Millican from LT1intake.com to machine the intake so I can run a distributor and bypass the opticrap!! But, I think that I will have the Edelbrock's ported and polished and go 383....See, my nieghbor is parting out his 95 formula and he has a salvage yard engine in it with 25,000 miles that he says he will sell to me for 400$$. Just had a head job cause he ran it hot and wants to sell it unassembled.....

I haven't started mine yet. I'm trying to make headers for the twin turbos that are sitting in the front seat of the car. I'm shooting for a thousand horsepower on 20 PSI of boost and 600 or so in street trim with only 10 PSI of boost (or somewhere in those neighborhoods). As far as machine work, I believe I paid around $600 to have the engine machined and assembled. I'll have to look at my receipts and get back to you.

Cool!!!! Mack daddy setup!!!! That thing will send many many people home with thier feelings hurt!!! Get back with me when you find out how much it costed you for the block work!!

Bro you have a lot of parts there...there are several ways to go.... BUt the heads go like this...


1. Iron eagles

2. Lt-1 stock

3. L98 stock

this is also the order of RPM limits... the Iron eagles will turn much better for you at RPM with that large cam....the lt-1 ok and the l98 will not help you....

remember the L98 is a torque motor... so if you build that with a 383 combo....YOU BETTER GET A TORQUE CAM.... you will be limited in RPM... it will be great on the street light to light... but you my be unhappy running heads up in the 1/4

You would get beat all day running against your high compression 350 with iron eagle heads and 306 cam with a 3000 stall and good gear 3.73 to 4.11...

WHY?? you will run out of air in the 383 and the 350 will continue to pull.... and catch you before the finish...hell would probably get you out of the hole....

the weight savings from iron to alloy on the heads will not net you anymore speed barely.... 100lbs is a .10-.05 difference in time..

Though the alloy will allow slightly better drivability (pump gas) and less detenation...which a good MSD system can help out a BUNCH!!

if you wanna run the L98 motor withe factory Fuel Injection, BUY THE GM FAST BURN HEADS... good flow...good rpm ability...and alloy.... you need the manifold base...and set down a notch on the cam...GM HOT CAM maybe this is just like the factory engine you buy from GM that is rated 380hp so you should put 300-310 to the wheels...moving to a 383 with this combo... and you should put close to 400 to the wheels...

GM sell the NEW 383 fast burn rated 460hp:eek: with a warranty...