Simple question about gathering parts for a 383 stroker. Am I better off buying a kit. Or should I just piece it together? Mainly looking at scat for the internals. I know i won’t be making more than 500 hp. So I plan on getting the cast crank. But my machinist recommended the scat pro comp 7/16 rods. Said it’s a better rod. None of the kits have this combination so thus the reason for the question. Plus I can’t afford a whole kit at once so also figuring get a little at a time. It’s a one piece rear block.

 

You don't have to buy a kit, you can piece and part it all up.

I believe my engine uses 3/8" Crower Sportsman Forged rods, I make a little north of 500 crank.

 

thank you sir that’s exactly what needed to hear. Now I can stop driving myself nuts. 🤣

 

Fwiw 2002~ LM7 engines are nearly free, support 550-650rwhp reliably in daily driver configurations using S364 to S366 size Borg Warner turbochargers for 200k - 300k miles like normal trucks. Using low lift, slow ramp rate, single lightweight spring, increased reliability at higher rpms due to exhaust cushion (the bane of natural aspiration and especially long stroke is RPM).

I built one using ~$159 Engine, the LM7 with 175k miles (now it has almost 225k at 520-620rwhp) and it functions equally well as a demo car for this particular cookie cutter combo.

I'm not trying to change your course. But I thought it appropriate to point out that factory connecting rods from 2002 super affordable LM7 engines are 650rwhp capable, and also that 2005-2007 L33 5.3L Aluminum Silverado engines are -120lbs lighter and have Gen4 connecting rods which can easily 1200rwhp if you are a master tuner using alcohol fuels and every trick.

That is to say, factory rods from 2005-2007 Gen4 style are generally 1000rwhp capable even in modest hands, which is the topic discussion (low hp for connecting rods worries) and present this as an option to save money and reduce down time in your adventure (you can be installing the engine tomorrow instead of waiting on machine work and mistakes for weeks or months and reduce responsibility of others towards your projects)

 

The 7/16 bolt Scat Pro Comp I beam rods are profiled differently on the big end and offer way more clearance at the pan rail and up at the camshaft. This is because they use a shorter OAL bolt than the 3/8 bolt Scat Pro Stock rods. Thats why your builder is recommending them. I highly recommend and use the Scat Pro Comp rod for builds in the 450-600hp range. The price is very reasonable for what you get.

I never recommend people buy kits because you have little choice in the individual parts. It's easy but you may not get everything you need or want. I have helped lots of members here with engine builds and many have bought the parts over time like you want to do and everyone worked out great. One guy took many (I do mean many) years to get everything before he reconnected with me about finishing the build and he now has a great running build.
Will

 

Hey Charles, when we built your engine we used Crower sportsman stroker rods. They have 7/16" rod bolts. They don't make that rod anymore. It was a great rod for stroker builds. Strong and cleared the cam and block well. A 383 about any rod will work, you probably have to clearance the shoulder of the rod a bit. Not a big deal. But a 3.875 or 4.00 stroke, I usually use a small journal rod so it clears the cam and block better. And you want a rod with a stroker rod design to it.

 

I agree. Even without boost a junkyard LQ4 with a cam will make 450-500 hp. At my local yard you can get those for $300 any day of the week. If your goal is under 500 hp there are way less expensive options then a 383.

 

There is a bit of a problem trying to use LS rods in a first gen or LT build. The LS rod length is 6.098, which is kind of a odd ball length. Most early sbc pistons are designed for a 6.00 or 5.70 rod length. There are also 5.85 rods out there too. Your piston selection won't be very good trying to use LS rods in a earlier L98 or LT1 type engine. You can get custom pistons, but they are pretty expensive. Its cheaper and easier to use a 5.7 or 6.0 rod

 

hehe thats why you use the entire $300 engine and forget the SBC.

The SBC can never match an LS in terms of reliability ,efficiency, sealing, oil control, stability, etc... No matter what parts are put inside.

This is because the main powerful feature of an LS (02+ engine) is the block itself. The girdle and pan support of the crankcase system allows the LS to use tighter clearances and thin lightweight oils and achieve a high RPM with reliability. Improved seals including piston ring and cyl wall design theme allow superior oil control. Advanced (modern) combustion chambers increase efficiency (LS engines require much less timing than SBC because of this) allowing control of high pressure situations (forced induction). And then there is the coil over plug, individual phase fuel injection capability, and the speed of modern microcontrollers packed into a $60 ECU from the salvage yard. The list goes on. The SBC is out.

 

You don't have to sell me on LS engines, I have a C6 LS3 car too. And they do respond very well to mods. I have also built my share of LS engines. But I still like old school sbc's

 

I have a question on this actually... Seems you can find the 6.125 rods easily enough. I'd imagine if you simply find a piston that would work it could be made to work as long as the compression height is right... right? A friend of mine (an myself because I'm curious but going a different direction) also has a set of .030 LS pistons in a 1.115 compression height. Now with a 6.0inch rod those would possibly work in a standard deck block with his 3.8 crank. Idk why he would want to other than cheap and has all that stuff on hand. He doesn't know, I don't really know, was just a drunk thought in the garage one night. But all the parts are there to do those pistons on gen 1 6.0inch rods. Because if it can work... I may buy them from him lol. I imagine there is more to it than I'm aware though and wouldn't mind being educated.

 

The formula for figuring compression height, rod length:
Deck height = 1/2 stroke + compression height+ rod length. So say a 383 with 9.00 deck height a 3.75 stroke use 1.875, and if you want a 6.125 rod would need a 1.00 compression height to zero deck it

 

Fair enough. 1 inch is awfully tight. maybe the LS pistons 6 inch rod combo will be better if that works out. Cheaper too.

 

I have been trying to find out if I buy a stroker with a Holley Sniper to replace my L-98 will the hood close without cutting a hole in it? I am going to buy a crate motor dyno'd at 450 hp. Stock exhaust because I do not like headers. I live in a rural area so I can remove cats and smog pump.

 

What kind of fuel delivery system did you use for the Lq4 engine and did the hood have to be modified? Will it drop into a C4? If I could use my TPI and get 450 HP that would be sweet.