Resdoggie on this forum has a 355 with AFR 195's, Howards roller cam .560/.560, duration 227/233, 10.6 compression and his 355 produced 360 RWHP (NOT Gross/NET) on a mustang Dyno which actual produces much lower RWHP numbers than a dynojet. You do know that 360 RWHP from a SBC C3 on a mustang dyno is a lot more than 450 Gross HP? My builder's mustang dyno consistently shows 400 RWHP with stock LS7 427 SBC Z06 motors that are rated at 505 NET HP, not Gross. Couple more examples for you.......I know wrapping around a traditional 355/383 making pretty stout Gross HP numbers with modern parts does not dove tail easily with traditional thought but the numbers do not lie......

 

I went through the same decision last fall when wanting to build a 383. I did a detailed list of parts with prices and found it was cheaper to just buy a crate engine. I went with a Blueprint 383. Very happy with it. I wanted to build the bottom end, but with time constraints I really didn't want to put the time into that part of it so I bought the short block and built it from there. My experience - you will spend a lot more than you think you will. Add up every set of bolts, gaskets, and all the other stuff you end up replacing and it adds up! But it was fun and I love it now.

 

I agree with Jim^^^^ that unless you have the time, need new crank and rods, and want to spend the money, A crate 383 is probably the most economical way to achieve your objective. If you have a good foundation like l did with my L-82 forged 350 as a base than building a stout 355 for the street is the decision I made over the 383 since I had a forged crank and L-82 rods to reuse. Converting a solid 350 L-82 into a 383 is not going to be "a little" more money as is often claimed. Between a good strong 383 crankshaft, 383 rods and engine/machine work, the conversion is not a few hundred dollars for 28 more cubes but more likely an easy $1,000-1,500 over keeping the 355, unless you are doing the machine work yourself. Just my thoughts....

 

Gents:
the low/no-budget junior OP hasn't seen fit to return in the 4 Months since he began thread / quasi-pipedream.

I'm with L88's suggestion but seems little else positive's actually been accomplished here.

Again & again ad nauseum ... some of same ol' repetitive braggadocio strut masquerading as help.

 

One more time, a 383 can be built with same rods as a 350. My 383 has my original 77 L48 connecting rods in it. They were simply resized on the crank journal end and fitted with ARP bolts.

 

My numbers matching L-48 350 was standard bore when it spun a rod bearing and ruined the crankshaft. The machinist said the block needed .030 to clean the cylinders up. So at this point I needed new pistons and a new crankshaft. At that point and for the money I was having to spend it was a no brainer to get the Scat stroker kit. I will add the fact that a 355 will never rev like a 383 stroker no matter what you do to a 355 and the extra 28 cubes is just a bonus.

 

I am curious what you mean the 383 will rev better than a 355?

The shorter stroke 355 will rev much easier, quicker, and smoother to a higher RPM than a stroked 350/383 with its longer stroke enabling the 383 to make slightly more power at a slightly lower RPM, about 300 RPM less for the additional 20 TQ over the 355, for identically prepared 355 and 383's (key point).

 

One more time from previous posters on the 383 builds: Stock rods can be used but not the preferred method......

"Depends on a number of things but, yes, is possible. 3 main areas of concern are rod to block clearance, crank to block and rod to cam clearance.

Crank to block can be tackled by using an aftermarket crank specifically built and clearanced for a 383 stroker. The 383 stroke is 3.75". Rod to block clearance can be tackled by either (a) using stock 400 SBC rods (5.565") but that rod length is not preferred, or buying aftermarket 5.7" rods already clearanced for the block. Stock or std aftermarket 5.7" rods can be easily found, but mock-up and relieving of the rods and/or block may be likely needed in a few spots if they aren't already relieved. I only noticed recently that they are available - in the past most of us bought rods, pistons with proper pin height for stroker and then spent extra time with mock up and clearancing.

Rod to cam can be addressed with the pre-clearances rods, using the shorter 5.565" rod or by using a cam ground on a small base circle. Ultimately the 5.7" rod (or longer 6" aftermarket) is the preferred rod choice for a couple of reasons (piston dwell and side-loading).

Others will chime in with their opinions. If it were me, I would opt for SCAT or other aftermarket crank (cast is fine for street applications), a 5.7" steel I-beam rod already relieved and talk to the vendor for input on cam clearance. I have used a small base circle Ultradyne hydraulic in the past with the long rods, worked fine, but also requires a longer (typically +0.100") pushrod. Regardless of parts you choose, it is critical to mock up the assembly following machinework to check clearances -- no matter who tells you they are bolt-in parts."

I personally would not use a cast scat crank if I was building a 383. A forged scat crank is $700 and the machine work on the stock rods plus labor is not going to happen for less than $1,000. A forged scat crankshaft with 5.7 forged rods for the 383 crankshaft plus forged pistons is $1,800 for the parts alone! https://www.summitracing.com/parts/s...05bi/overview/

As I stated, if you need to replace everything from the 350 donor engine, then the conversion makes a lot of sense to a 383 but the concept that the conversion is just a few hundred dollars more is in most cases, not true......

 

I will agree to disagree with you on every point. I really don't understand why you think a .030 over bore 350 is a better build than a stroked .030 over bore 350. A 383 stroker will absolutely smoke a 355 even if it is identically prepped and will hit the rev limiter much faster. Have you ever built and raced a 383 stroker? I have.

 

I have not raced a 383 stroker but technically the 355 should rev faster and higher than the stroked 383 which naturally would have slightly more TQ at a slightly lower RPM. This capability is true of any shorter stroke engine than a longer stroked one...this point is not debatable.

I do not think that a 355 is a better build than a 383. What I have always said is the difference in identically built 355/383's is not as great as is often purported to be and what the numbers consistently demonstrate. Of course, an identically prepared 355/383 with the same parts will have the 383 always come out on top but that is rarely the case with engines in real life, since there are so many variables.

I will try once again to illustrate what I always try to point out with 355's versus 383's on this subject. A 383 with average aluminum 195 heads, along with 9-9.5 compression and flat tappet or roller cam of .501/.510 lift or less, 225/230 duration, LSA 112 will make XXX HP under 6,000 RPM. If you take a 355 and build it with 180 or 195 AFR/Dart high end aluminum heads with superior peak and low lift flow, 10.5+ compression, and a roller cam of .560/.560 Lift, 228/233 duration, LSA 108, that 355 will make XXX HP which I guarantee will be more than the 383 previously described, across the board. The 28 additional cubes and longer stroke of the 383 cannot make up the power difference of the 355 with higher performance parts and specs...not happening which is why you can go to a drag strip and a potent 355 will smoke most 383's........See the difference and how it can occur?

A 383 has the potential to make more power than a 355 but unless they are built identically to match the cubes, that is rarely the case, which is why you see so many variations in engine configurations of all makes, displacements, parts for these engines etc across the spectrum of manufacturers and independent racers........there are so many ways to get performance from so many engine configurations.

Yes, all things and everything be equal and exactly equivalent, the 383 OF COURSE can make more power than a 355 but the cubes number alone does not ensure the 383's superiority.............AND it costs more than a few hundred dollars for the conversion....

 

Fixed it for you.

There is a SLIGHT difference in piston speed due to the increased stroke. There is a NOTICEABLE difference in torque due to the increased displacement.
As long as you're starting with a bare block and pair of heads, there's NO reason not to build the bigger engine since you'll have to buy a crank, set of rods and pistons. You can bet your last dollar that if NASCAR allowed more cubic inches, they would build them right up to the allowable limit. Since bore size is limited by bore spacing, they'd have to add stroke.

As for potential RPM, I've watched many 632 cubic inch monsters revved to 7500rpm on an engine dyno. Built with good parts, long stroke engines can rev and make massive power. Flame travel speed and valvetrain control are more limiting factors than stroke.

 

I went to Northern Auto Parts for my stroker kit. Here's the link to the kit I purchased 3 years ago for $646.00: http://www.northernautoparts.com/part/ek-ek1921

I felt it was a great value for quality name brand components. Kit came with Seal Power flat top hyperutectic pistons. Since then I've learned I probably should have gone with forged but have had no problems. I've been very careful with timing setting to avoid detonation issues and run 93 octain fuel

I also took a gamble on a pair of somewhat unknown fully assembled 64cc Flo-Tek aluminum heads https://www.flotekheads.com/store/Sm...4cc-p130678684s . I match ported heads and intake to a Fel-Pro 1206 intake gasket. Ends up I couldn't be happier with them as they contain all the goodies that go into AFR's for less than half the price. They were $740 for the pair (wow) and included stainless swirl polished valves, 2.02 Intake and 1.06 exhaust, multi angle seat grind, bronze guides, top end stem seals, dual springs good to .600 lift, push rod guides, and screw in rocker studs.

Flat tappet lifters and Comp roller rockers. (I would have gone full roller but that's an additional $450. Maybe a later upgrade.) Performer air gap intake, headers, and 2500 stall converter. The reputable shop that did my balancing gave me a conservative estimate of 450 flywheel HP. Compression ratio was 10.8 static 9.6 dynamic according to online formulas.

I'll call this engine very street-able with power to rock when you want it. When the quadrajet secondaries open you better be ready and holding on.

I'm 15K miles down the road now with zero issues still running 80 psi oil pressure. I hope this gives you some ideas. Good luck with your build.