Experiences? Switching to synthetic in a high mileage LT1
Your major retail stores won't have what you are looking for. I would order off Summit/Amazon etc if you can't find it local.
I'm probably looking at going with a Motul 600 Brake Fluid and Red Line Power Steering Fluid.
As for the oil, I'm definably going to go with a 10w-40 or higher weight oil. Still not sure on a brand or whether or not to go synthetic but if I do, I'm probably going to go with something designed for higher mileage cars with additives to help preserve seals.
An oil temp and trans temp gauge are in the works, I even have another gauge bezel I got at the swapmeet that I'm going to try and integrate them into for a somewhat factory finish (I hate pillar pods).
I'm also looking at oil coolers, I've been reading that the black Moroso coolers that came on 93-94 LT1's are better than the 95-97 OEM coolers. I'm also open to suggestions if anyone has had any luck with any aftermarket coolers.
It would be wise to look into sandwich adapters that have internal thermostatic switch which routs oil to the cooler at a predetermined temp. Then run a cooler at the front of the car. Allows oil to heat up properly then maintains the temps.
Also, I had issues with oil leaking THROUGH my Low Oil Level sensor in the side of my oil pan. So I searched around and found a male to female adapter to plug this hole then run a standard 1/8" NPT temp sensor. Maybe not optimal location for oil temp sensor, but it was the easiest place to start getting readings. Need a M20x1.5 to 1/8" NPT found it from KillerBMotorsports
Oil Cooler - Double checked my car and it comes with the factory black Moroso cooler that came on 93-Early 95 F bodies. After some research, it doesn't sound like that bad of a cooler, it doesn't clog easy and it's low restriction, which is the opposite of what I hear about the later aluminum F body coolers. I'm going to get an oil temp gauge and if it does well, I'm going to keep it for now. Maybe I'll do something better down the road when the 383 goes in or if it doesn't perform well.
Oil - I was considering going synthetic but I think the fact that the car has some mileage and oil seepage issues, this may cause some more issues than it's worth so I'm going to play it safe and go with a semi-synthetic 10w-40 weight oil for the current motor. I was looking at Driven XP7 but it's pricey (avg $11/qt.) and I need to order it (shipping & down time). What I think I'm going to do instead is run Castrol GTX High Mileage which can be picked up at Walmart for less than $20 for a 5 quart jug, since it's cheap and readily available, before every event I'm going to add a quart and after every track event, the oil will be changed. If I pay for the XP7, I'm not going to want to change it every event so it's a choice between using a cheaper oil and changing it more often or using a more expensive oil and changing it less often. Since both are still conventional based, I'd like to change it more often after a hot track day. I use K&N Performance Gold oil filters and if I change the oil after every event, I'll probably change the filter every other oil change. Again, this is what I'm doing for my high mileage stock LT1, when my 383 is done, it'll be a fresh motor and I plan to run a good full synthetic oil (Amsoil, Driven, Redline) after break-in.
Power Steering - I will be installing a frame rail mount cooler and flushing the entire system with Redline power steering fluid.
Brake Fluid - I was looking at MOTUL 600, but after going to my local performance shop, I ended up picking up a few bottles of StopTech Racing STR600 which is a DOT4 fluid with just about the same dry and wet boiling temps as the MOTUL.
The July event I was shooting for was canceled, and I'll be on vacation for the August event so the car will be on the track in September and October. I'll keep everyone updated on how the fluids hold up
Buy a proper B&M stacked plate cooler and NOT a cheap 3/8" inlet/outlet tube and fin style cooler. It is REAL easy to aerate the fluid in cheap coolers and it will sound like you have a roots blower under the hood not to mention your pump will hate you. Ask me how I know

I run a 1/2" inlet/outlet B&M stacked plate cooler roughly 10" wide, 1" thick and maybe 4" tall. I mounted it in front of the AC condenser using rivnuts on the lip of the lower radiator support. Ran all new 3/8" lined with Russel AN fittings from rack to cooler and cooler to reservoir. I also picked up a PSC deflowed PS pump to reduce flow rate and heat...but that may come later for you.
Make sure your cooling system is up to snuff, maybe 160* thermostat and have the fans come on sooner. And or add a manual fan switch. Keeping coolant happy SHOULD keep you oil temps in check to a certain extent.
Switched to dino Mobil Super 10-30 and the leaks stopped. I think synthetic exposes any weaknesses in gasket sealing ability!
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I'm currently doing research on power steering coolers so I'm definably going to look into what you're running, that sounds like a real good setup. The pump will probably come when the 383 goes in.
Already have a 160 t stat and I plan on wiring in a fan override switch. I would like to tune the fans to come on sooner but I have found nothing solid on what to use or how to do it on an OBD1 LT1.
In OP's case where he is on a 200+ TW tire in a 275-ish width size. Doubtful all that is needed. PLENTY of people road race without a setup like that.
Plus the fact that I own a '98. I believe there were some oiling problems because of the windows in the lower end not being big enough for the engine to properly maintain pressure under high, sustained G loading. I believe they first noticed it in the Corvette in '97 and finally remedied the situation by '99 or so. My brother in law has a full blown gutted/caged C4 he races at Mid-O and has one mounted up against the fire wall under a fabricated dash....but again that's a fully stripped purpose built car.
But yes, it would be good insurance, but in the mean time a good oil/oil temp and pressure gauge AND add a road race baffled oil pan would help.
My brother in law has a full blown gutted/caged C4 he races at Mid-O and has one mounted up against the fire wall under a fabricated dash....but again that's a fully stripped purpose built car.
But yes, it would be good insurance, but in the mean time a good oil/oil temp and pressure gauge AND add a road race baffled oil pan would help.







