Throwback Thursday: A Guide to Aftermarket LS Blocks


The LSX block was the first LS block to offer six bolts per cylinder for head retention—note the extra bolt bosses cast into the top and bottom sides of the deck surface. If you’re running high boost or a load of spray, the extra bolts help keep the head gasket from blowing out.

Welcome once again to Thursday. It’s that time of the week when we open the Chevy Hardcore vault, take a step back in time, and locate an article that you guys might have either forgotten about, or might not even know exists. Whichever the case, we are certain that you will enjoy this editorial flashback.

I decided that this week, we should take a look back to 2014, and visit at an article that all gearheads can find chock full of valuable information – A Guide to Aftermarket LS Blocks


The prowess of the LS engine has been proven time and time again. The power making capabilities of this engine – even in stock form – is awe-inspiring. It is not uncommon to hear about engines pushing 1,000 horsepower, and still be using stock components. Now that is impressive. But, there is always room for improvement, and that is where the aftermarket lends a hand.


Racing Head Service has been in business since 1967, but they’re all modern with one of the most popular LS blocks on the market.

In the original article, Rob Kinnan begins by touting the virtues of the LS platform, and even dares Mopar and Ford guys to dispute the power making capabilities of the LS, “It’s hard to argue with anything about the GM LS engine. Traditional Chevy vs. Ford vs. Mopar guys can bicker all they want about the old-school engines, but no sane person can say that the LS does not have the most power potential of any engine out there, especially on a cost-per-horsepower basis.”


The LSX block uses six bolts to secure the crankshaft, four vertical and two horizontal (per main cap) for a solid bottom-end package. Improved over the stock block are vents between the main saddles to help reduce power-robbing windage.

Anyway, Rob discusses aftermarket blocks from companies like World Products, Dart, RHS, and even Chevrolet Performance. We were surprised to read how Richard Maskin of Dart Machine feels the stock LS block is pathetic. That’s a strong sentiment, and you’ll have to read about why he makes that claim, and how the situation is corrected.

When it comes to Chevrolet Performance, Rocko Parker talks about how they looked at the design of the production block, and re-engineered it to arrive at the LSX. Bill Mitchell Jr, was more than happy to talk about how he improved an already impressive design, “Although the BMP LS aluminum block was already made from the alloy 357-T6 and has already been on the dyno producing horsepower numbers in the neighborhood of 2,500 (which are in the range only a cast-iron or a billet version would normally be capable of), I wanted it stronger!” You’ll have to read the original article to find out how he accomplished that feat.


Dart has a billet block for the LS, but the LS Next is their new, affordable block for the masses. According to company owner/founder Richard Maskin, the LS Next is far stronger and has much better oiling than the factory piece.

There is a lot more information to glean in the original article, but you’ll have to check it out to get the whole story. So, take a look back at, A Guide to Aftermarket LS Blocks, and find out what’s available, and what you should know about each offering.

About the author

Randy Bolig

Randy Bolig has been working on cars, and involved in the hobby ever since he bought his first car when he was only 14 years old. His passion got him noticed by many locals, and he began to help them with their own vehicles.
Read My Articles

Hardcore Chevys in your Inbox.

Build your own custom newsletter with the content you love from Chevy Hardcore, directly to your inbox, absolutely FREE!

Free WordPress Themes

We will safeguard your e-mail and only send content you request.