Hey guys,

Thinking of replacing engine as the stock 350 is not cutting it. Leaks a little oil and rough start up...

I have heard that a big block with the added 200#'s up front really messes with the agility, nimbleness and handling of the car.
So with that I am interested either in a Small Block 427 with Throttle body F.I. from White Performance on ebay 600+ HP (Base is a Dart Block)
Or
A LS 364 from Ross Performance on ebay 550+ HP (Stock LS block).

I read an article from the founder of World Products stating that the oiling properties of the LS design was terrible. The LS takes an average of 18 quarts/min circulation whereas the SBC only 6 quarts/min!!! (Yet, when you look at the performance results of the LS engines they are hard to beat...I suppose from the cathedral head design).

The other issue of comparison is that the SBC will eventually leak from the valve covers, rear main seal and possibly the pan. I can't stand leaks and messes entire chassis up eventually. The LS seals are obviously better.

I spoke with both vendors and they both build and sell numerous engines on a regular basis. Skip White apparently has a ton of high dollar equipment they utilize on every build and the Dart Block is a plus. I also like the old school look a lot better for our style cars. (Can't stand the coils on the valve covers but I have heard Summit sells remote mounts).

Ant inputs/comments/suggestions greatly appreciated!!!

Thanks!

 

https://www.ebay.com/itm/CHEVY-TURN-....c100005.m1851


https://www.ebay.com/itm/CHEVY-LS-CR...S/233045977097

 

That near $1800 difference in cost would tend to steer me towards the LS engine.

 

Well the LS motor is a engine "swap". But the sbc is just a replacement. In my book that's a big difference in effort/work for similar power. You have so many more parts that just bolt on and bolt up to another sbc that you will have search and maybe modify for the LS motor. I don't see leaks as a definite problem as I've had good luck with extra thick valve cover gaskets. I learned how to cut rope seals on my Pontiac and now offset main seal parting lines and use anaerobic sealant for the main cap so to me I just don't expect leaks there w/o high mileage use.

Just my 2 cents.

 

Good point converting over to a LS swap.

This Vette has side pipes and to get LS headers to match up with the side pipes would take a lot of FAB work!

 

True! The other parts will eat up the $1800 difference quick.

 

sbc 427. only way Id do an LSx swap was for big CI..maybe.
Not hard to get say 600 out of a stroker sbc these days, thats more than most can put to the ground anyways. Make it easy, plus it will look proper
LOts of big block conversions too dont let the soind of weoght discourage you there is no replacement for that big low end tq like a BB.
You can cam one up pull a tall gear and operate most times at part throttle its too much fun. plus that thunderous exh note you only get from a BBC
Unless youre a corner addict you wont notice the difference of BB or SB. Once you have a BB car rarely will a sb take its place.

 

 

Aluminum heads on a BBC and you are very little heavier than iron head sbc. More work than replaceng with another small block. Waaaay less than LS conversion.

 

Its always fun spending other peoples money.

There's very little cost difference going from a 350 to 427 gen1 small block or from a 346 to 427 LSx... about $500 for the rotating assembly plus incidentals. Apples to apples a 427LSX will make more useable friendly power than a 427Gen1 sbc. I've only owned 2 LS powered cars, a LS1 Corvette and a LS2 GTO. 400hp form an LS is nothing like 400 from a Gen1

That all being said, depending on skill levels the conversion cost of an LS conversion can low.....or high.

 

I would go LS. Look forward Move ahead. It's been out for 20+ years.

I don't want to guess, but are you already leaning towards the SBC 427? Just an impression I'm getting the way it is written?

 

I would go LS. I did a LS2 sleeved and stroked to 427 cubes. LS3 heads. 235I 24oE 114CL .615 lift cam. Made almost 500 hp to the rear wheels. I know not huge numbers but was easy to tune. No surging at low speeds. The only reason I would go 427 SB is if you wanted to maintain the stock look of the engine.

 

You are better off going to skip white directly. A friend bought the hottest cam 434 from Skip White and when it had valve to piston problems skip white warrantied the whole thing.

I am Pro raised cam Motown and Dart blocks when you start doing these 4 inch or more stroker motors. Years ago and I don't know if they are around anymore in the Sonoma area was BadAss Motors. Well anyway they built a 4.125 stroker SBC that you could get in 441 or .030 over bore at 447 or .060 as a 454.

I had to go Gen 1 style because I have headers, intakes, dizzy...…. So what would I do with my stuff if I went to LSX? Dry sumping on LS is an advantage as well as the better heads. I use a 4 quart Accusump on my Motown 434 and a 8 quart pan and filter setup

 

Anything over 500 hp and the frame will twist...

I would go with a built SBC around 475 Hp.

 

Its fun to throw ideas around and that's why I love this forum, but only you can decide which way you want to go. They are both good. I have the 427 small block and I love it. Yes it leaks a little oil. (I've never been able to completely seal a Gen 1 small block for long.) But I like opening the hood and its just a small block. I would never find fault with someone who chose the LS route. That would be cool too.

 

Something along these lines might make a good option...

All-Aluminum SBC 427 cid short block 4.125 x 4.00 4340 forged

Good luck... GUSTO

 

Many choices, but do what gives you the most comfort. Personally, I went the 440 small block route because the car was originally a 350 and everything just bolted up. I love the horsepower (close to 700), and have no problem with leaks. I'm old school, so I'd never put an LS engine or anything computer controlled in my '69. But, if this current engine ever needs replacement, I will seriously consider a big block...more horsepower potential.

 

 

Since you are in Vacaville, call John and visit his shop at LJ's Speed and Machine in Napa (707) 255-4611.
John and his team have been building racing engines of every type for over 50 years.
Tell John what you want and he will custom build you the perfect engine for your needs.
I've seen everything from blown and injected monsters, to LS motors, to vintage MG's, Model A's and he won't hesitate to help a fellow vineyard owner when he needs his John Deer rebuilt.
LJ's is highly respected throughout the racing/custom industry, they are honest and not over priced.
Greg