Gurney Weslake engine?


New Member
I recently acquired a 1923 model T as it was parked in a neighbors garage rotting away. He said the engine was a gurney Weslake 302. I haven't spent a lot of time on it yet because I would like to know what I have. The time I have spent tinkering with it the weber 48 Ida carbs were expensive and difficult for me (new to this)

I'm not sure what I want to do with this engine yet.... Can anyone help me out?

I'm willing to provide as much info as I can. Mostly just curious to what this is worth?


Yes those are GW mk4 heads. They are most likely to be the later AAR road version cast by A&M rather than the WM cast race version as fitted to GT40s (see differences here Gurney Weslake Homepage ). The Webers will be worth most if they are period Italian ones - check for numbers stamped on the cartouche at the base. As for the rest of the engine, check the block part number to identify if it is anything special - XE or Boss 302 say. The rest would require engine disassembly to determine. Value? $15k upwards - you still have to find someone to pay!


New Member
Thank you for the response.

I have read other forum topics and I have checked the block and cannot find the stamped numbers. The rear side of the motor is tightly up against the body which makes it difficult. If I knew exactly where to look it may be easier to find. As for the Webers, would the cartouche be on the outside or inside of the carbs?

I looked at the difference between the two heads and see very little difference. I assume the easiest way to tell is the stump coming out?

I will look as soon as possible and report.
Block code is above the starter motor. Since your carbs are mounted fuel entry to the outside you will have to look on the inside faces of the carbs.


New Member
Ok so I couldn't find the casting numbers anywhere so I removed the starter and still found nothing. Could they be under the paint? I took a picture so if you know where to look I will remove the paint and find it. P.s. How should I remove the paint without scratching the numbers?

The carbs are stamped with the 48 IDA 4 With the numbers 1824; 1213; 1286; 1616

I don't know what those numbers tell me.

Also, I believe I have road car heads


Jac Mac

Active Member
If you strip the paint off that casting number pad you might be able to read the number 'shadow', but it looks like its been 'de-burred', next external clue would be size- width & dia- of crankshaft damper outer ring- if 289 hp it is very close to front of timing cover & extends further fwd than pulley bolt face ( 3 bolt pulley ). Freeze plugs in block suggest a 289 Hi-Po at best I think.... Mexico block had three cast bolt lugs facing forward at front of block, usually undrilled- one just in front of oil filter pad & two on the non pump-filter side. What trans is it running and how many bolts attaching bell housing to block- 5 or 6?
Good news on the carbs: 48 IDA-4 = 37mm chokes and the serial numbers indicate they were made between 1966 and 1970. Apart from the desirability of period correctness, these carbs are far better made and finished than the later ones from Spain.


New Member
How would I go about stripping the paint properly? should I buy some paint stripper and apply it and gently remove with a brush?

Also, the entire segment on the crankshaft diameter and width might as well be written in Chinese to me and I apologize for that. I know what the crankshaft is, I'm just not sure what I would have to do to get to that? Do I need to remove the harmonic balancer?

As for the 3 cast bolt lugs on both sides of the motor, I looked and found some flat spots but they do not face forward. I took Pictures but I'm guessing these are not what you are referring to. see pictures. (I apologize for giving the finger):laugh:

I am running a C4 Trans and it has 6 bolts on the bell housing.

That is good to hear I have quality Carbs.


What a cool find! Even if its just a standard, garden variety 289/302 block, that is a really cool head/intake combo.

Try to take a close up of the crank dampner. Your larger lower crank pulley is bolted to it. A good look at that should let you know if its a K-code 289hp, or not.

The numbers you are looking for above the starter should be a stamped VIN#, not a casting #. Most of the k-code mustangs had the block stamped with the VIN#. At the end of the day, other than the VIN#, a hp block is nothing special. Its the bolt on parts that make it special. (ie: main caps, crank balancer, crank damper, etc)

Jac Mac

Active Member
Water pump pulley in post #11 has C5-- (1965)p/n plus damper & front cover 'look' like items from that era... which would suggest that its a plain jane 1965> 289 motor, nothing wrong with that, just is what it is!


New Member
When I bought the car the guy told me it was a 302 or a 305. Any chance it still could be or anything relatively simple I can do to really be sure?

Jac Mac

Active Member
Stroke is 3.00" for 302, 2.87" for 289, so you might be able to check that with piece of wire thru plug hole. 289 can have 302 crank fitted to make it a 302... 305 would be 302 + 0.020" or 0.030" rebore, only sure way would be pull pan and check/measure stroke or crank numbers- you could pull heads but cheaper to pull pan, video camera with probe would show piston crown & valve cutouts & possibly stamp for oversize bore to someone with weslake experience.

Mark R

New Member
Looks like a 70's era timing cover to me. I can double check but thought the 60's covers had a bolt on timing pointer. Also, thats deffinately not a HiPo crank dampner.

Its got a pretty exotic head/intake combo. My bet is the seller would have know if it was a HiPo block and would have deffinately talked it up on that point.

My best guess would be early 70's 302, but you never know whats inside.

Bore scope down the plug hole might tell you something. but as long as its running well, your probably ok.
Well looks like I'm back on this topic again.

As of late, I'm trying to identify what heads I have. I believe them to be the road version.

This first picture is on the back side on passenger side of car. because of clearance it is difficult to get a good look. I may remove them this weekend.

All help is greatly appreciated.