Maybe it's worth considering ? 22,75" OAL, including accessories ! Torque is good for street machines and this does quite well. Popular in Fieros, why not in LBC's ?
Let's discuss, Art.
I was thinking Jim Nichols did suggest the Caddy 4.9L a good while back.
My project is being resurrected again for my 15 year old grandson. Doing structural floor and rocker work now. Probably 4.9 Caddy with V6 60 degree 700 R4 at first but I already have a Jeep AW4 too. You can also use a 200 R4 with Speedway adapter. Stay tuned!
Refresher course.
http://forum.britishv8.org/read.php?6,13482
I just spent a good part of the morning rereading that entire 11 page thread. Jim Nichols has compiled a fantastic amount of information on Caddy 4.9L mods!
1990-4-5-engine_orig.jpg
Nice work Jim ! Did you use the 4.5L. intake manifold for the 4 bbl.? It appears the rod journals have " hydraulically rolled fillets".
I found KB pistons and billet rods that should work. My round lobe, RV8 cam blanks might be modded to fit. This
engine begs for a good alumium head !
Onward, Art.
Art, That is one of John's Performance motors. He used an adapter from TBI to 4 barrel. The 88-90 4.5 have the TBI and straight valve covers. 4.1 had painted or chrome straight valve covers. The 91-95 4.9 has the same TBI pattern but you have to plug the injector holes with pipe plugs. Here is the adapter: https://khaosmotorsports.com/collections/air-delivery/products/holley-edelbrock-carburetor-to-tbi-intake-manifold-adapter
4100 oil pan looks nice:
https://youtu.be/5xLKMh82kLg?t=462
Not a fan I'm afraid, it appears to have a number of questionable design features that I'm just not happy with, and that look like they would be difficult or impossible to change. Things like the small oil passages in the filter adapter and the cantilevered design of the rocker support bar come immediately to mind as worrying for any sort of performance build. For the MGB I think the Rover is a better bet and in the same weight and displacement range with lots of aftermarket support.
Having said that I'd take a Buick 300 over either of them. I'm not just saying that, I sincerely do believe it is a better fit for the car.
Jim
The 4.1 (4100) had a lot of issues. Most were fixed by the time the 4.5 came out in 88. I do like the chrome valve covers and oil pan, also the water pump and exhaust manifold. The valve covers can retrofit to the 4.5. There are other parts that may help a longitudinal swap. The rocker bar issue is solved by machining a notch for pedestal rockers and better bolts. The 4.9 oil pump should be used in the 4.5, gerotor type with more volume and pressure, less load on distributor.
rockernotches.jpg
I like the 300 Buick too, but age and scarcity has taken it's toll. car-part.com wrecking yard search of entire country list eight, but 13 pages of 4.9 Cadillac.
Looking in the wrong places. TA has a list of warehouses around the country who have old Buick engines and parts. I just sent them an email asking if they will share that list, we'll see how they answer.
Jim
From Hemmings in 2018:
Buick Parts Resources
https://www.hemmings.com/stories/article/buick-parts-suppliers-part-1
https://www.hemmings.com/stories/article/buick-parts-suppliers-part-2
https://www.hemmings.com/stories/article/full-size-buick-parts-suppliers
Loyalty vs. engineering : The reality is, the RV8 , Buick V6 and SBB are based on engineering of 1960 +/-. Seemingly Rover dolled-out improvements as a must. Their larger bore with aluminum core shift is a basic problem.
Not really Art. Upgrades are available for those who want them. Surely there must be something better than that single plane above? Such Tiny throttle bores.
Jim
Reportedly the 60 deg., V6 flywheel can be re-drilled to fit the Cad. Try SBF hedders, modded to fit. New oil pan , $20. on Rock Auto. Cylinders are cheaper/easier to bore and hone. What if there was a SOHC head available soon ? Got a lathe, make your own aluminum flywheel, with Fidanza steel insert.
Onward, Art.