Mopar 273-4bbl Combo

[larrylomascolo]

I had a friend who,s dad owned a 68 dodge dart,273 4spd,hub caps,14 inch bias ply green with black vinyl roof,we would take it out after his dad went to sleep,pushing it down the road,We raced a few guys with the dart and that little screamer being bone stock was impressive,good combo but like Paul said get your wallet out

[James L Miller]

Boy, everyone is telling me to get the wallet out. I think I have $40 in there or maybe a bit more. It looks like the rods and pistons might be some of the big ticket items. It looks like Melling has some 1/8" wall sleeves that would reduce a 318 stock bore (Ø3.91") down to the 273 range (Ø3.66" or so). I'm thinking using Hardblok in the wimpy 273 blocks will be a cheaper way to go. The Hardblok is about $100, sleeves are around $20-40 each, plus machining. I'll see what my machinist/engine builder wants to do, but the Hardblok looks like a less expensive way to beef up the thin cylinder walls. I wonder if the later 273 blocks had thicker cylinder walls?

[Paul Wong]

delete

[Terry Bride]

I'm slowly working on this same combination for a 66 Barracuda.

You need to keep in mind that the sleeve will need a step to retain it in the parent bore. You can't stick a 3.910" O.D. sleeve into a 3.910" bore. There will be nothing to support the sleeve. You will need a sleeve with enough oversize beyond the parent bore dia. to allow an adequate step to register against. I have not found any straight sleeve with enough wall thickness to do this. In this case, the only way to do the sleeving correctly is to get a set of flanged liners and counter bore the deck for the flange.

A custom sleeve will be an expensive investment along with some fairly substantial machining costs but in the end, you will have a block that will maintain it's bore size for many re-hones.

I will have to sonic test the 1967 273 block I have to see what it has for thickness.
In the mean time, I am saving up to purchase the pistons and maybe sleeves.

[James L Miller]

I did catch my engine builder while he was taking a break at the beach on the east coast of Florida. He was thinking along your lines but using a 340 block and get custom sleeves with the flange as you mentioned. That would be really stout cylinder walls for a 273 size engine. He said he did that many years ago when he ran his Colt in MP with a 280 CID (3.935" bore, probably the old 2.96" stroke crank) with W2 heads. I wasn't sure how big of a step was needed at the bottom near the main webbings.

I think I will start with a 273 block with Hardblok on the first go. I don't want to spend a ton of money on this project. The idea is to run quick enough to qualify in Div. 4 divisional and national events here (don't plan on going to Indy).

[Frank Castros]

James,

I also love the combination and wish you well with your build.

Sleeving a 340 X block would be the ultimate, but very expensive (if you can find one) Hardblock in a 273 is the way to go on a budget.

Also speak to Dean Oliver about a carburetor.

No disrespect to all who have offered their advice but Paul Wong is the guy I would consult.

[grncpe]

I have looked at this combo for a while. What style header are you going to run? There were some fender well headers for them but choices are limited now. The primary tube diameter being to large from a 340 is a problem. Luckily for you guys I have the stahl fixtures & masters for the early a cars with a small block 😋. The 66 valiant sedan in ss looks like the best combo to me. The problem is committing that much money to that engine program. With a x block & Honda rod journal, killer heads & intake, and lots of rpm. The package is light enough to be a killer! But what old killer package is cheap? None.....

[James L Miller]

Thanks for the info on the carb. Matt had mentioned Deano did his carb. Now I know he meant Dean Oliver. I have some 340 blocks, used to have a TA block, but sold it to a restorer in Houston many years ago. I'm going to go with the Hardblok. Thinking about using K1 rods and CP pistons. Not sure about what bore size and what rings? Anyone make spacers to fill the 5/64ths groove with a 1mm or 1.2mm top ring?

The Edelbrock head looks like it might be a good future upgrade with only a 5HP hit. It will add some 68 pounds to the car, but with my fat butt driving I think it will be heavy already. I wonder if Edelbrock sells the head without the valve seats installed?

I see that TTI, Dougs and Hooker makes headers for the early A-bodies. I didn't see anything on the Stahl site. I think they are all 1-5/8" primaries. The TTI looks like it has the best plug access. All are $600-$900. No cheapie headers for that combo.

[David Lee]

Originally Posted by grncpe

I have looked at this combo for a while. What style header are you going to run? There were some fender well headers for them but choices are limited now. The primary tube diameter being to large from a 340 is a problem. Luckily for you guys I have the stahl fixtures & masters for the early a cars with a small block 😋. The 66 valiant sedan in ss looks like the best combo to me. The problem is committing that much money to that engine program. With a x block & Honda rod journal, killer heads & intake, and lots of rpm. The package is light enough to be a killer! But what old killer package is cheap? None.....

what is your definition of cheap?

[grncpe]

$600-900 is cheap for headers in comparison to others out there. The west coast stainless headers are $ 3400 just an FYI. You won't see any headers on stahl' site. All the fixtures were sold. I bought all the Chrysler fixtures along with all the collectors stahl had. I'm not trying to sell headers on here just saying that may be an option for you. I allready have one person that contacted me about building a set. I think I may have some 273 parts left if you need some. I would like to see this combo out there, I think it would be cool if it had a stick behind it also!