a walker

I am planning out the rebuild of my LT1 that I will be doing soon. I am weighing the options of just doing a budget 355 with some good heads and a cam, or going all out and building a 383 or 396.

I have been looking around and pricing the parts, and I am a little confused. Some places I see stroker kits made specifically for LT1's, and they are considerably more expensive than those for a standard SBC. What's the difference? I always thought that the LT1's rotating assembly was the same as a SBC, with the exception of that the LT1 is internally balanced, where the SBC is externally. Is that the difference? If so, could I buy a SBC kit and use an ATI or similar dampner?

Another question...I have also seen cranks with a stroke of 4.00". Anybody ever heard of a 408 LT1? That would be something different from everybody else, and the crank wasn't a whole lot more than the 3.85" stroker.

mebanditws6

You can buy the 400 cranks (3.75" to make a 383) as cast in addition to forged for gen sb's. As far as I know, forged cranks are the only types you can buy for LT1's which would explain the difference. IMO, it defeats the purpose of going with a cast crank for a stroker. Not only can they not support as much hp and rpms as forged, but they really don't cost all that much less than a decent forged crank from Eagle.
Jason

TQdrivenws6

There are many cast cranks for the LT1. Scat is a popular one, and will cover most peoples needs.

The 4" crank will need a ton of work to fit, you will have to hard block, and likely move the cam bearing bores for clearance. There is a good reason that people generally don't go bigger than the 3.875" which sometimes is even pushing it due to core shift.

Do you know what heads you are going to use? If you say ported stock heads, then go 355, as the port cross section will have a hard time keeping up with a 383.

a walker

Thanks for the info. I figured there was a reason that people werent going bigger with a stock block.

I plan on using the Trick Flow heads. My original plan was to just do heads/cam with the TF heads and a 847 or XE 236/242 cam, but then I realized that it was be pretty retarded to do heads/cam on a 184k mile bottom end. So I started considering my options. I don't have a lot of money to spend, so I was considering just a freshening up. Then I realized it wouldn't be much more money to just do a 355, since the only thing extra needed was a set of pistons/rings and the bore. Then I started thinking that if I bore it, I am only a crank and block clearancing away from more cubes. So, I figured I would spend the extra money now and do it the right way (the way I have always wanted it) rather than have to do it all over again in a couple years. So, right now, I am leaning more toward a 396 with the TF heads (out of the box) and the 847 cam. I will then re-jet the nitrous up to a 200 shot or more.

mebanditws6

What do those heads flow?

Jason

blazzinbird

hey aron, im in the sam eboat as you, right now im looking at piston and rings right now, hoping maybe the conecting rods will be good. Dont have alot of money, but want to put my nitrous over a 200 shot. I weiging in on maybe the speed pro kit from summing, then some new rods and a cranks. I just hoping that the block work wont kill me, cause we all know im not rich.

anyways about the tf heads
195cc intake port
75cc exhaust port
62cc combustion chamber
2.02intake/1.60exhaust

assymbled 1,359.95
bare 895.95

FASTFATBOY

Porting the stock heads will outflow the TFS heads and will be cheaper.

www.killiansportingservice.com

see above you will not be disappointed.


David

a walker

True, they may flow better than out of the box Trick Flows, but they will be maxed out, while the Trick Flows can still be worked and blow away the stock castings.

93turbo5oh

i wouldnt bet the farm on that one. those trick flows look like a standard 23 degree casting just like all the other LT1 heads that are already on the market. for a stock displacement or small stroker (think 3.875" stroke or less) LT1 its gonna be hard to beat good set of ported stockers with the right port cross sectional area and flow numbers.

FASTFATBOY

I wouldnt go so far as to say that....I know where a set of stock castings are that flow OVER 300 CFM with a 2.00/1.56 Valve, they run 10.60's all motor on a 383 in a 3200lb Z28.

ANd will go low 10's when the bugs get worked out.

David

Formula03

Just so you know you can either forged or cast for an LT1, any SBC with a 1 piece rear main seal will work in an LT1. The cast cranks are fine for anyone who will not be throwing a ton of N2o at it. It seems to be a common misconception that everyone that builds a 383 needs a forged crank, they dont. A cast will hold to around 550-600 hp if it is balanced good and it is backed with some 6" rods(they put less stress on the crank). I have a cast steel eagle crank and it is a very nice, stout piece and can be had for around $220 new form Seco Performance.

93turbo5oh

the only thing i dont like about the 6" rods is that you give up piston compression height, which causes the piston to rock around at BDC more and can wear rings out faster.

Formula03

This is true but you can kinda counter act this by putting good rings (moly they will take more abuse and last longer) in it and I would rather have to replace the rings than deal with a snapped crank.

93turbo5oh

good point, but thats why id run a forged crank.

Seal

yeah, with the addition of this and that u can spend 50-60 bux more and get a forged crank