Engine Block Cracked

[Supercharged111]

Take this for what it's worth: back in 2015 I found I'd wadded up a rod bearing. My motor is a 93, I believe it was 95 when they changed the rotating assembly but don't quote me. I nailed a late LT1 crank on Craigslist and had it polished. I found a set of stock takeout pistons and rods on eBay. I installed new rings and bearings, gave the bores a 3 stone hone job 320 grit with moly rings. Didn't measure a damn thing and that's the motor you saw my car run at Hallett. On a motor that needs to be restricted, perfection isn't really necessary IMO. Mine made 292whp unrestricted in 2016. I'm 1 plate size larger than I was then. Is it the book answer? No. But to an extent, good enough is good enough in our class. YMMV.

[64GunPilot]

Im not looking to build power obviously, just reliability. Im not usually a lucky person, so putting it together without taking measurements, my luck something would be x10 beyond a tolerance and the engine would self destruct on the dyno. Problem is I never done this before, and I don't know typical limits of what is normal.

I just ordered a kit with new pistons. Will throw it together and see how it turns out.

[64GunPilot]

Jealous not being able to come and attend Hallett this year.

Being deployed I have too much time to think about racecar stuff. Ive been building a 5.3 and getting ready to do the swap. I came across a good deal on an LT1 complete turn key with accessories and T56 trans and bought it. The trans needs rebuild, but was thinking about what if I bolted up the LT1 to the T5 currently in the car. Would the T5 survive? Most seem to think it would not survive behind the 5.3. I would assume the same behind an LT1. Just asking what ya'll think. Some other forums have folks who thrash on the LT1/T5 and say it seems to survive but thats probably on street tires and street conditions. The LT1 would be so much more simple in terms of engine mount, trans bolt up, driveshaft mod ect. (Ive read plenty about the optispark issues and torqhead is an expensive fix).

Im still planning to do the 5.3 but just window shopping other ideas.

[Fbody383]

Survive is relative - yes it will work until it doesn't. Will you need a different bellhousing? I think you'll need a customer transmission mount because I believe the T5 is canted over 20ish degrees.

PS - our experience is that optis are not as bad as they're made out to be... Does Lingenfelter still have these? https://www.lingenfelter.com/product/BAI-LTCC.html I didn't call to see.

[64GunPilot]

Survive is relative - yes it will work until it doesn't. Will you need a different bellhousing? I think you'll need a customer transmission mount because I believe the T5 is canted over 20ish degrees.

PS - our experience is that optis are not as bad as they're made out to be... Does Lingenfelter still have these? https://www.lingenfelter.com/product/BAI-LTCC.html I didn't call to see.

Isn’t the LT1 the same bellhousing bolt pattern and depths as every other SBC? I’ve been running the old 305TPI with T5. From what I read I thought the LT1 bolts right up bellhousing flywheel clutch and all. I may have misunderstood something here. I guess I need to do some more digging. I got Time. I’ll do some more research.

[Supercharged111]

I'm under the impression that the LT1 should bolt in and go unless they're balanced differently in which case you'd be in it for a flywheel. My Opti was installed in 2014 (knock on wood), but it was an AC Delco that they quit making.

[BryanL]

Paging Gary. He ran the T5 behind his LT and should know what's needed along with if it will last.

It will definitely work-but maybe like the Ford's that used to always bring a spare T5 (especially at Hallett).

I'm racing an LT now. I remember a conversation with Mitch about them sorting out the opti issues but don't remember what they did-Glenn probably knows. Do you have the complete pullout with wiring harness?

Nice find OIF - https://www.bailey-eng.com/product/l...der-converter/

[Alien]

Isn’t the LT1 the same bellhousing bolt pattern and depths as every other SBC? I’ve been running the old 305TPI with T5. From what I read I thought the LT1 bolts right up bellhousing flywheel clutch and all. I may have misunderstood something here. I guess I need to do some more digging. I got Time. I’ll do some more research.

Your 305 is a 1pc rear main, correct? I can't remember if all TPI's were the later style.
Yes, the T5 bellhousing bolts right up to the LT1, and the T56 bellhousing will bolt up to the 305.
Canton pan fits both 305 and LT1

I've run my (world class) T5 for a few years behind the 305. I did go through it and did some of the standard upgrades (bearing retainer I think?) quite a few years ago when I dropped in the LT1. A lot will depend how you drive it to make it survive. No sidestepping the clutch on the standing starts, don't just slam your shifts.

I'm using the T5 clutch and hydraulics. I took the flywheel to get balance matched to the LT1 flywheel, just to be sure. Don't remember what they did, but that particular flywheel was on a few previous engines.

5.3L is nice and if something major happens I'll go that route. As mentioned, the longblock is the cheap and easy part. It's all the other stuff that adds up. Exhaust and intake manifolds if you don't have them, custom y-pipe, engine crossmember notched (sometimes), trans crossmember (Holley is great, but interferes with my Alston subframes), accessories, oil pan and Improved trap door for oil control, hoses, wiring...

[64GunPilot]

Your 305 is a 1pc rear main, correct? I can't remember if all TPI's were the later style.
Yes, the T5 bellhousing bolts right up to the LT1, and the T56 bellhousing will bolt up to the 305.
Canton pan fits both 305 and LT1

I've run my (world class) T5 for a few years behind the 305. I did go through it and did some of the standard upgrades (bearing retainer I think?) quite a few years ago when I dropped in the LT1. A lot will depend how you drive it to make it survive. No sidestepping the clutch on the standing starts, don't just slam your shifts.

I'm using the T5 clutch and hydraulics. I took the flywheel to get balance matched to the LT1 flywheel, just to be sure. Don't remember what they did, but that particular flywheel was on a few previous engines.

5.3L is nice and if something major happens I'll go that route. As mentioned, the longblock is the cheap and easy part. It's all the other stuff that adds up. Exhaust and intake manifolds if you don't have them, custom y-pipe, engine crossmember notched (sometimes), trans crossmember (Holley is great, but interferes with my Alston subframes), accessories, oil pan and Improved trap door for oil control, hoses, wiring...

Gary, thank you for the confirmation. Everything I’ve read says it’ll work. Nice to have a fellow racer onboard with the idea. I’m $4000 into the 5.3 build. I probably should just finish it out. Just need another $1500 worth of crap, and then I might be ready for the Dyno. Time, effort, and money. Striving for reliability. Can’t make up my mind.

[Mojave]

Jealous not being able to come and attend Hallett this year.

Being deployed I have too much time to think about racecar stuff. Ive been building a 5.3 and getting ready to do the swap. I came across a good deal on an LT1 complete turn key with accessories and T56 trans and bought it. The trans needs rebuild, but was thinking about what if I bolted up the LT1 to the T5 currently in the car. Would the T5 survive? Most seem to think it would not survive behind the 5.3. I would assume the same behind an LT1. Just asking what ya'll think. Some other forums have folks who thrash on the LT1/T5 and say it seems to survive but thats probably on street tires and street conditions. The LT1 would be so much more simple in terms of engine mount, trans bolt up, driveshaft mod ect. (Ive read plenty about the optispark issues and torqhead is an expensive fix).

Im still planning to do the 5.3 but just window shopping other ideas.

Why would you ever want to run an LT at all? If you are dropping the money on a Torquehead LS computer swap.... why not just go straight LS?