HIgh Compression is a good start. I have a 351 with Gas research twin carby setup and had it dyno'd about 4 yrs ago with 360hp at wheels. Changed heads to closed chamber, TRW flat tops, rollers, crow stage III gas cam, some crank work and a few other bits and pieces.
Goes like a rocket, burns clean and cheap to run!!

 

What gear box and diff gears are you running?

I reckon it is achievable, but depends on what else you have in your drivetrain and will cost a few $$$.

 

What is current engine setup?

By using 302 heads you can bump the compression up to around 11:1.

Use an impco 425 bolted onto a holley 850 base. If you desire or require, you can run two. The Impco 425's are worth about $50 at swapmeets.

The car will have similar fuel costs to a small hyundai.

 

hmm interesting concept, has anyone done this on a stroker? cause i wanna do a 383 but with fuel costs these days i think im better going with LPG.... how much power can be achieved with a 383 on lpg using extensively ported 2V heads with suitable good springs dampners etc, good cam, and good manifold (weiland or funnelweb) plus extractors etc
im thinking somewhere around 300hp at wheels with butloads of torque? what do you think? im very keen on this idea..

 

hmm interesting concept, has anyone done this on a stroker? cause i wanna do a 383 but with fuel costs these days i think im better going with LPG.... how much power can be achieved with a 383 on lpg using extensively ported 2V heads with suitable good springs dampners etc, good cam, and good manifold (weiland or funnelweb) plus extractors etc
im thinking somewhere around 300hp at wheels with butloads of torque? what do you think? im very keen on this idea..

People have done it on 460ci fords, so a stroker shouldn't be a challenge.

If can't afford petrol for a 383 than obviously can't afford a 383.

 

i can thats the thing, im just a tight ass and dont like spending money on something that i can get cheaper..

 

To save me re-typing everything there's another post in the cleveland forum i've put my opinions in regarding straight LPG clevelands.

Hope it helps,
Greg

P.S. I hope to be running into the 13's on straight LPG and a single impco 425 (ported out to flow more gas) on may 15th. I'll let you all know how I go!

 

that will be every interesting xdc351. It seems the norm to have 2 impco 425's? correct me if im wrong

 

Ive never seem 2 impco 425's on anything other than a tunnel ram.

If your local rego authorities don't have a problem with your manifold and carbies poking out the hood or you can find a twin carby manifold then you can run 2.

Impco make a T bar setup then can run 2 300A mixers, but i've never seen one run and it doesn't look very good.

 

If you want an example of twin impco 425's have a look in the latest extreme magazine which you can usually pik up from autobarn which has a stroked 351 windsor that puts out more than 500 horsepower

 

Thats the other thing about twin 425's.

Each carb tends to flow more than 425cfm's... so you'll need a setup so wild it'd need a 950-1050 cfm petrol carb! Not too many around on the streets with a combo that wild.

Thats one of the reasons the dual research kit is so popular... its much easier to adjust the mixture to run richer/leaner and the 'carbies' come in 3 different sizes so the exact cfm rate can be achived.

 

well i have to do a rebuild on my engine so im thinking about goign the good out 4.0 scat crank and putting twin impco 425's on it

 

What is more suitable in a straight gas set up- single or dual plane manifolds? I have been told that single are better with open plenum for gas...is this true??

Curious myself as am shortly rebuilding my clevo with straight gas.

 

Single plane is better most of the time. Most LPG engines have pretty good low end response or a stallie, so there's little to gain from a dual plane but plenty to gain from a single plane when you start revving hard.

 

Just read your other post xdc351 on clevo gas....good read.... I`ll stick with my xcellerator.

 

Lpg vaporises at low temperatures so a dual plain isn't required to provide an adequete signal to the carb. As lpg vaporises so readily, it also take up more volume, hence the use of single plain manifolds.

 

FatJake I got a dual throttle Gas Research 351 XE that does 13.6 on street tyres through the mufflers AND is for sale...pm me for details